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FARM   FRIENDS  AND 
FARM   FOES 

A  TEXT-BOOK  OF  AGRICULTURAL  SCIENCE 


BY 
.RENCE   M.    WEED,  D.Sc. 

STATE   NORMAL   SCHOOL,   LOWELL,    MASSACHUSETTS 


D.    C.    HEATH    &   CO.,   PUBLISHERS 
BOSTON         NEW  YORK         CHICAGO 


COPYRIGHT,  1910, 
BY  D.  C.   HEATH  &  Co. 

l-D-2 


W3 


PREFACE 

THIS  book  is  intended  to  serve  as  a  text  and  guide  for 
the  study  of  those  plants  and  animals  so  vitally  related  to 
crop  production  as  often  to  determine  success  or  failure 
therein.  The  information  given  embodies  the  latest  re- 
searches of  that  host  of  investigators  who  have  done  such 
great  service  in  the  advancement  of  agriculture  in  recent 
years.  The  text  has  been  so  combined  with  directions  for 
observation  and  expression  that  it  is  hoped  that  teachers 
will  be  able  to  lead  their  pupils  to  a  first-hand  knowledge 
of  the  most  important  plants,  insects,  birds,  and  mammals 
to  be  found  in  the  region  of  the  school. 

Most  of  the  original  engravings  are  from  drawings  by 
Mr.  W.  I.  Beecroft,  a  few  being  adapted  from  the  publica- 
tions of  authors  to  whom  credit  is  given  in  the  list  of  illus- 
trations. Many  of  the  insect  pictures  are  from  woodcuts 
originally  made  for  the  classic  report  on  Insects  Injurious 
to  Vegetation,  by  Dr.  T.  W.  Harris,  for  the  use  of  which 
thanks  are  returned  to  Mr.  J.  Lewis  Ellsworth,  Secretary 
of  the  Massachusetts  State  Board  of  Agriculture.  For 
courtesies  in  connection  with  other  illustrations  I  am  in- 
debted to  Misses  Hazel  Dearth,  Alice  Manning,  and  I.  S. 
Cragin,  and  Messrs.  James  Hall,  A.  G.  Randall,  E.  D.  San- 
derson, A.  D.  Selby,  A.  H.  Verrill,  and  C.  W.  Woodworth, 
as  well  as  to  the  Experiment  Stations  of  Illinois  and  New 
Hampshire  and  the  United  States  Department  of  Agri- 
culture. I  have  also  to  thank  Mr.  W.  F.  Fiske,  of  the 
Gypsy  Moth  Laboratory,  for  kindly  reading  the  proof  of 
the  chapters  on  Predaceous  and  Parasitic  Insects. 

247015  c.  M.  w. 

iii 


CONTENTS 

PART  I 
FRIENDS  AND  FOES  AMONG  THE  WEEDS 

CHAPTER  PAGE 

I.  THE  WEEDS  OF  ROADSIDES  AND  WASTE  PLACES  i 

II.  THE  WEEDS  OF  MEADOWS  AND  PASTURES     .        .        .  .13 

III.  THE  WEEDS  OF  GARDENS  AND  CULTIVATED  FIELDS     .  .      31 

IV.  THE  WEEDS  OF  GRAIN  AND  FORAGE  CROPS  ...  .      45 
V.  THE  ECONOMICS  OF  WEEDS    .        .        .                .        .  .55 

PART  II 
FRIENDS  AND  FOES  AMONG  THE  INSECTS 

VI.    ORTHOPTERA:    THE  GRASSHOPPERS,    CRICKETS,   AND    COCK- 
ROACHES      ,    •    .        .        .        .        .     '  .        .        .        .      65 
VII.    HEMIPTERA:  THE  TRUE  BUGS         .        .        .        .        .        -73 
VIII.    THE  BUTTERFLIES  AND  MOTHS       .        ...'>.        .96 
IX.    THE  Two- WINGED  FLIES 122 

X.      COLEOPTERA:    THE   BEETLES 13! 

XI.  HYMENOPTERA  :  THE  ANTS,  BEES,  WASPS,  AND  SAWFLIES       .     149 

XII.  INSECTICIDES  AND  THEIR  APPLICATION 155 

XIII.  THE  PREDACEOUS  INSECTS      .        .        ...        .        .        .163 

XIV.  THE  FOUR- WINGED  PARASITES 174 

XV.  THE  TWO-WINGED  PARASITES 188 

XVI.    THE  POLLINATION  AND  FERTILIZATION  OF  FLOWERS     .        .194 
XVII.    THE  INSECT  POLLINATORS 203 

PART  III 
FRIENDS  AND   FOES  AMONG  THE  FUNGI 

XVIII.    THE  MUSHROOMS,  TOADSTOOLS,  AND  MOLDS         .        .        .215 

XIX.    THE  DOWNY  MILDEWS 219 

XX.    THE  SMUT  FUNGI 226 

XXI.    THE  RUSTS 231 

v 


VI 


CONTENTS 


CHAPTER  PAGE 

XXII.    THE  ASCOSPORE  AND  OTHER  FUNGI 242 

XXIII.  BACTERIAL  DISEASES  OF  PLANTS.        .        .        .        .        .  229 

XXIV.  PREVENTIVES  OF  FUNGOUS  DISEASES   .        .        .        .        .  264 
XXV.    FUNGOUS  DISEASES  OF  INSECTS    . ' 271 

XXVI.    BACTERIA  AND  PLANT  FOOD        ......  275 

PART   IV 
FRIENDS  AND   FOES  AMONG   THE    BIRDS 

XXVII.    THE  RELATIONS  OF  BIRDS  TO  FRUIT  ORCHARDS         .        .  285 

XXVIII.    THE  RELATIONS  OF  BIRDS  TO  MEADOWS  AND  PASTURES    .  291 

XXIX.    THE  RELATIONS  OF  BIRDS  TO  GARDENS  AND  FIELDS         .  296 

PART  V 
FRIENDS  AND  FOES  AMONG   THE    MAMMALS 

XXX.    THE  SQUIRRELS     .        .        . '    ;V  -    v       .  '     .        .        .  307 

XXXI.    THE  MICE  AND  RATS  .        .        .        .        .                .        .  312 

XXXII.    THE  RABBITS,  POCKET  GOPHERS,  MOLES,  AND  SHREWS      .  321 


BIBLIOGRAPHY 
INDEX 


328 
329 


LIST   OF    ILLUSTRATIONS 

PAGE 

Monarch  Butterfly.  From  Nature  Biographies  .....  xi 
Cover  Design  for  Booklet.  From  a  Japanese  Stencil  ....  2 
Dandelion  Seedheads  ....  •--'%  *  ...  5 

Burdock 7 

Broad-leaved  Dock •     .   ,    .        .        .        .         8 

Evening  Primrose 10 

Toadflax  or  Butter-and-Eggs  • II 

Milkweed  Pods        .         .         .      '  .         .         .  .         .         .         .13 

Sprig  of  Johnson  Grass.  Redrawn  from  Cates  and  Spillman  .  .  14 
Squirrel-tail  Grass  ...........  15 

Cone-flower 16 

Canada  Thistle        .         .         .         .         .         .        .        »        .        .         .18 

Milkweed  Seeds      .         ^         .         .  .         *        .         .         .         .21 

Sheep  Sorrel  .         ...         .         »         .         .         •         .         .         .22 

Hardback .24 

Poison  Hemlock .         .         .         .26 

Poison  Ivy.    From  Drawing  by  A.  G.  Randall        .         .    .     .         .         .27 

Quack  Grass 31 

Pigeon  Grass » 32 

Shepherd's  Purse 33 

White  Pigweed        .         .         .         .       '. 35 

Ragweed 37 

Clotbur 38 

Ground  Cherry  or  Physalis      .........       40 

Jimson  Weed .         .         .         .         . 41 

Gill-over-the-Ground 44 

Mixture  of  Weed  Seeds.     From  U.  S.  Department  of  Agriculture          .       46 

Meadowsweet          .         .         . 55 

Spud       .         .         .         .         . 56 

Broad-leaved  Dock.     Redrawn  from  Henkel 59 

Goldenrod  Seedheads 61 

Cover  Design  for  Booklet  on  Insects 64 

Mouth  Parts  of  Grasshopper 66 

vii 


viii  LIST  OF  ILLUSTRATIONS 

PAGE 

Grasshopper :  Nymph  and  Adult ,        »         .       66 

Oblong  Leaf-winged  Grasshopper.     From  Harris .         .         .        .         -67 
Common  Cricket.     Female.     From  Harris    .         .         .         .         ,         .       68 

Tree  Crickets :   Male  and  Female.     From  Harris 68 

Mole  Cricket.     From  Harris .         .         ...         .        .         .         .70 

Squash  Bug     .         .         .         *    ,    •«     '• .  •-,  ..',.  •»      •'•    '     •>    •  V        .         .       73 
Chinch  Bug.     From  Harris   .        .         .        .        .  .         .         •       75 

Map  showing  Distribution  of  Chinch  Bugs.     After  Webster    ...       76 
Periodical  Cicada    .         .         .         ....'."      '.         .         .       79 

Tree  Hoppers.     From  Harris        .         .        .        .        ••         .         .       80 

Scale  Insects  on  Rose     ,        .         .         .         ,         .        »-.-.,.       83 
San  Jose  Scale        .         ...         .         .        .         .         .    •     .         .84 

Black  Scale     .         .         »         .         .         .         .         .        .        .         .         .       85 

Spring  Grain  Aphis.     Redrawn  from  Webster        .         .         ...       88 

Eggs  of  Apple  Aphis       .         .        .-,..,.         .         .         .       91 

Ant  attending  Aphides   .         .         i         .      '  .        .         .         .         .         .92 

Elm  Leaf  affected  by  Aphides .         .93 

Cicada  emerging  from  Nymph  Skin.     Photograph  by  A.  H.  Verrill        .       95 
Promethea  Moth  Cocoon         .         .         .         .         .        .         .         «         .       96 

Orange-dog  Caterpillars.     Photograph  by  A.  H.    Verrill.         .   '      .         .       98 
Butterfly  of  Orange-dog  Caterpillar.     Photograph  by  A.  H.  Verrill         .       99 

Luna  Moth 102 

Tent  Caterpillar      .         .         .         .        .         .         .         .         ...     103 

Gypsy  Moth    .'....        .        .        .        .        .        .        .104 

Army  Worm   .         .         ;         .**,.»,         .         .        .         .         .     108 

Cutworm  Larva.     From  Harris      .         .    •     .        .        .         .         .         .no 

Cotton  Bollworm.     Photograph  by  A.  H.  Verrill in 

Codling  Moth          .         .         ,        ,         .....         .         .     113 

Apples  showing  Calyx  Open  and  Calyx  Closed        .         .        ...     114 

Leaf  Roller  Moth.     From  Harris  .         ...        .         .         .115 

Peach-twig  Borer.     After  Clarke    .        .         .        .         .         .        ,v      .117 

Tineid  Moth  .         .         .         .         .         .    .     .         .         .         .        »:  '    .     118 

Winter  Nest  of  Brown-tail  Moth     . 121 

Hessian  Fly    .         ....         ..         .         .         .         ..         .122 

Hessian  Fly  Magnified 123 

Apple  Maggot .-        .         .     125 

Channels  of  Apple  Maggot .     126 

Cabbage  Maggot.     Adapted  from  Washburn 127 

White  Grub  or  May  Beetle 131 

Lamellicorn  Beetle.     From  Harris 132 

Potato  injured  by  White  Grub 132 


LIST  OF   ILLUSTRATIONS  ix 

PAGE 

Rose  Chafer.     From  Harris.          ,       .  • 133 

Eyed  Elater.     From  Harris 134 

Leaf  Beetle.     From  Harris 135 

Colorado  Potato  Beetle  .         .        .        .         ..*.         .         .         •I35 

Flea  Beetle .         .     139 

Round-headed  Apple-tree  Borer.     From  Harris   .         ,         .         .         .     140 
Plum  Curculio          .         .         .         ....-       .         .         .         .     142 

Strawberry  Weevil.     Redrawn  from  Riley 142 

Peach  injured  by  Curculio        .         .         .         .         .         .         .         .         .     143 

Mexican  Cotton  Boll  Weevil  .         .         .         .         ...         .         .144 

Infested  Cotton  Square  .         .         .         .         •  ,,-,.         .         .         .         .     145 

Cherry  Sawfly          .         .         ....»         ..         ..     149 

Willow  Sawfly  Larva       .         ;         ....        .        .         .         .     150 

Head  of  Aphis.     Redrawn  from  Slingerla nd          ,         .         .         .         -155 

Bucket  Pump          .         .         .         .., 156 

A  Simple  Spraying  Outfit.     Redrawn  from  Marlalt       .         .         .         .158 
Powder  Gun    .         .         .         .         .         .         .         .*..•      ..         .161 

Tiger  Beetles.     From  Harris     .     . 163 

Ground  Beetles.     From  Harris       .         .         .         .         .         .         .         .     164 

Tiger  Beetle  Larva.     From  Harris         .     • 165 

Ladybird  Beetle  and  Pupa.     From  Harris 165 

Blister  Beetle.     From  Harris         .        .....        .         .         .166 

Soldier-bug     .         .        .         .        . 166 

Robber  Fly.     From  Harris    .         . 168 

Syrphus  Fly 169 

White-faced  Hornet.     From  Packard 170 

Dragon-fly ' 171 

Egg  Mass  of  Mantis        .        . 171 

Dragon-fly.     From  Harris 173 

Ichneumon  Fly  ovipositing  in  Cocoon     . 174 

Long-tailed  Ichneumon  Fly.     From  Harris 1 75 

Ichneumon  Fly  and  Chrysalis.     Photography  by  A.  H.  Verrill        .         .     1 76 

Ichneumon  Flies.     From  Harris 177 

Cocoons  of  Microgaster  Flies.     From  Harris 177 

Caterpillar  with  Cocoons  of  Parasites 178 

Parasite  of  Grain  Aphis.     Redrawn  from  Washburn      .         .         .         .179 
Chalcid  Parasite  of  Gypsy  Moth's  Eggs.     After  Howard        .         .         .184 

Pelecinus  Fly  . 185 

Tachinid  of  Army  Worm.     Drau<n  from  Photograph  by  Slingerland      .     1 88 

Tachinid  Parasite  of  Gypsy  Moth.     After  Fiske 190 

Cherry  Blossoms     . 194 


x  LIST  OF   ILLUSTRATIONS 

PAGE 

Structure  of  Cherry  Blossom .  195 

Pollination  and  Fertilization    .     '    . 195 

Cucumber  Flowers.     After  Drawings  by  James  Hall      .         .         .         .  196 

Strawberry  Blossoms        .         .         .         «         .         .         •"    •    »        •         .  198 

Pear  Blossoms 198 

Leg  of  Bumblebee  .         .         .         .         .         .         .         .         ,        .  202 

Bumblebee.     Photograph  by  A.  H.  Verrill     .         .         .         .         .         .205 

Easter  Lily ..*        .  209 

Pear  Leaf  Blight.     Redrawn  from  Galloway,         .         .         .         .         .214 

Mushroom ,        *         .        «                  .  215 

Mushroom  Spawn.     Drawn  from  Photograph  by  Atkinson      .         .         .216 
Mycelium  of  Mold.     Redrawn  from  Zopf      .         .         .         .         .         .217 

A  Dying  Mushroom         .         .         .         .         .         .         .         ...  218 

Potato  Leaf  affected  with  Late  Blight.     After  Galloway         .         .         .  220 

Spores  on  Leaf        ...........  221 

Smut  Sporidia          .         .        ,         .         .         .         ...         .         .         .  226 

Oats  Sinut       .         .         .'        ....        .         *.         .         »         .  227 

Corn  Smut.     Drawn  from  Photograph  by  Selby       .         .         .         .         .  228 

Spore  Germinating :  seen  from  Above.     Redrawn  from  R.  E.  Smith     .  232 

Spore  Germinating:  seen  from  Side.     Redrawn  from  R.  E.  Smith        .  232 
Black  Knot  on  Wild  Cherry   .         .         .         .         .         .  .:  . ..     .    .         .243 

Apple  Scab ...         .        ...  245 

Apples  dwarfed  by  Scab.     Redrawn  from  Chester 246 

Apples  affected  by  Bitter  Rot.      From  Scott,  U.  S.  Department  of  Agri- 
culture       247 

Brown  Rot  Spores  Developing        .         .         .         ....         .         .  248 

Brown  Rot  Spores  Germinating      .....         .         .,        .         .  248 

Potato  Leaf  affected  by  Early  Blight.     After  Galloway  .         .        .         .  255 

Bee's  Claw  with  Blight  Bacteria.     After  Whetzel  and  Stewart        .         .  260 

P'ly  with  Fungus .         ..-*..  273 

Soy  Bean  Root  showing  Tubercles.     From  Hopkins       .         ...        .  277 

Red  Clover:   Effect  of  Bacteria.    Drawn  from  Photograph  by  Hopkins  .  279 

The  White-throated  Sparrow.     After  Biological  Survey          .         .         .  284 

Tent  Caterpillar  Nest  attacked  by  Birds 287 

May  Beetle.     From  Harris 291 

Click  Beetles.     From  Harris 292 

Meadow  Grasshopper.     From  Harris 293 

Screech  Owl.     Photograph  from  Life       .         .         .         .         .         •         .  294 

Prairie  Dog  Burrow :   Sectional  View.     After  Merriam          .         .         .  306 

Field  or  Meadow  Mouse.     After  Samuels 312 

Wild  Morning-glory  Roots.     Drawn  from  Photograph  by  Lantz      .         .  314 


LIST  OF   ILLUSTRATIONS 


Hyacinth  Bulbs  eaten  by  Pine  Mice.  Photograph  from  Lantz 
White-footed  or  Deer  Mouse.  After  Samuels 
Cornstalk  ruined  by  Brown  Rats.  Photograph  from  Lantz  . 
Rat  Trap  used  in  Burma.  After  Lantz  .  .  .  •  .. 
Barrel  Trap  for  Rats.  After  Lantz  .  .  .  .  . 
Wellhouse  Rabbit  Trap.  After  Lantz  ..... 
Georgia  Gopher.  After  Biological  Survey  .... 


PAGE 
3^5 

319 
319 
320 
323 
324 


PART   I 

FRIENDS   AND    FOES   AMONG   THE 
WEEDS 


COVER  DESIGN  FOR  A  BOOKLET  ON  WEEDS 


THE  BOOKLET  ON  WEEDS 

Every  pupil  should  make  a  booklet  for  each  of  the  important  subjects 
taken  up  for  study.  The  booklet  should  be  composed  of  such  drawings 
and  language  work  as  is  done  in  connection  with  the  study  as  well  as 
mounted  leaves  or  other  specimens  that  are  readily  included  in  it. 

The  ordinary  plain  paper  used  for  drawings  serves  very  well.  A  good 
size  is  six  by  nine  inches.  Three  holes  should  be  punched  near  one  end  for 
binding  with  raffia  in  a  cover  of  thicker  paper. 

It  is  very  easy  to  get  material  for  the  booklet  on  weeds.  Characteristic 
leaves,  branches,  and  flowers  may  be  pressed  and  mounted.  Young  seed- 
lings also  may  be  preserved. 


FARM  FRIENDS  AND  FARM  FOES 

CHAPTER   I 
The  Weeds  of  Roadsides  and  Waste  Places 

ONE  of  the  commonest  sources  of  the  seeding  of  culti- 
vated lands  is  from  the  weeds  that  grow  in  such  abun- 
dance along  roadsides  and  on  neglected  ground.  A  great 
variety  of  weedy  plants  are  to  be  found  in  these  situa- 
tions, and  very  often  the  weeds  that  first  infest  tillable 
fields  come  from  the  seeds  of  these  plants.  Consequently 
our  study  of  weeds  may  well  begin  with  these  wayside 
plants. 

When  a  plant  is  common  and  widely  distributed,  one 
is  pretty  certain  to  find  that  it  is  splendidly  equipped  for 
the  battle  of  life.  The  Dandelion  is  a  good  example  of 
such  a  plant.  The  root  is  thick  and  tough  and  leathery, 
running  straight  down  into  the  ground  with  branches 
toward  the  bottom.  It  is  filled  with  a  milky  juice  and  is 
intensely  bitter  to  the  taste.  The  thickened  root  enables 
the  plant  to  store  up  food  one  season  for  the  sending 
up  of  blossoms  the  next.  The  tough  and  leathery  struc- 
ture enables  it  to  bear  trampling  by  cattle  without  injury. 
The  bitter  taste  and  milky  juice  protect  it  from  being  eaten 
by  insects  or  higher  animals. 

The  stem  between  the  root  and  the  leaves  is  so  short 
that  there  is  practically  none  at  all.  This  also  saves  the 
plant  from  injury  when  it  is  trodden  under  foot.  The 

3 


.     t » 

4  FARM 'FRONDS  AND  FARM  FOES 

leaves  are  spread  out  in  a  rosette ;  the  lower  ones  are 
the  longest;  the  margins  are  deeply  cut;  they  are  bitter 
and  filled  with  a  milky  juice.  The  rosette  habit,  the 
longer  lower  leaves,  and  the  incised  margins  all  help  the 
plant  to  get  the  most  benefit  possible  from  the  sunlight ; 
while  the  bitter  taste  and  milky  juice  render  the  leaves 
unfit  for  animal  food. 

The  Dandelion  flowers  are  borne  on  hollow  cylindrical 
stalks  filled  with  a  similar  bitter  juice  and  covered  with  a 
woolly  coating.  By  means  of  the  hollow  cylinder  the 
greatest  strength  is  obtained  in  proportion  to  the  amount 
of  material  used,  while  the  woolly  coating  makes  the 
ascent  of  ants  and  other  wingless  creatures  difficult. 
Several  rows  of  green  straplike  bracts  surround  the 
flower  head,  forming  what  the  botanists  call  the  involucre. 
With  the  help  of  these  bracts  the  flowers  close  at  night 
and  in  rainy  weather.  This  saves  the  pollen  from  being 
washed  away  by  the  rain,  and  probably  helps  the  plant 
by  preventing  radiation  of  heat.  A  large  number  of 
little  flowers  are  crowded  together  to  make  up  what  we 
call  the  blossom,  thus  rendering  it  so  conspicuous  that  it 
is  freely  visited  by  bees,  which  carry  the  pollen  from 
flower  to  flower  and  thus  bring  about  cross-pollination. 

When  the  little  ovules  have  been  fertilized  by  pollen, 
the  Dandelion  closes  up  for  a  time  in  order  to  ripen  its 
seeds.  Then  the  flower  stem  lengthens  rapidly,  generally 
carrying  the  closed  head  above  the  surrounding  grass. 
'When  the  seed  ripens,  the  bracts  open  and  the  round 
"blowball"  appears,  ready  for  the  wind  to  carry  the 
seedlike  akenes  away. 

It  is  not  strange  that  a  plant  with  these  advantages 
should  become  a  weed,  crowding  out  others,  and  claiming 
all  the  space  and  light  and  moisture  wherever  a  few  Dande- 


WEEDS  OF  ROADSIDES  AND  WASTE   PLACES        5 

lions  become  established.  To  a  greater  or  less  extent, 
practically  all  the  other  weeds  have  similar  advantages, 
and  one  of  the  interesting  things  about  the  study  of  each 
is  to  find  out  what  these  advantages 
are.  This  will  often  point  the  way 
to  the  best  means  of  checking  the 
increase  of  the  plant. 

The  Dandelion  also  illustrates  an- 
other general  truth,  namely,  that  the 
way  in  which  we  think  of  a  plant 
depends  upon  our  point  of  view.  To 
farmers  and  to  the  owners  of  lawns, 
the  Dandelion  is  a  weedy  pest,  fit 
only  to  be  exterminated.  To  gar- 
deners, it  is  a  profitable  crop  plant, 
worthy  to  be  carefully  cultivated. 

To  physicians,  it  is  a  storehouse  of 

r    J  DANDELIONS 

remedies  for  human  ills.  To  bota- 
nists, it  is  a  species  of  great  interest  because  of  its  adapta- 
tions to  the  conditions  of  plant  life.  To  artists  and  poets 
and  many  other  lovers  of  nature,  it  is  of  inestimable  value 
in  decorating  the  landscape  and  lighting  up  the  fields  with 
its  wonderful  disks  of  gold. 

SUNFLOWER  FAMILY 

The  Dandelion  is  a  typical  example  of  the  great  group 
of  plants  called  the  Sunflower  family,  or  Compositae.  The 
principal  character  of  this  group  is  the  association  of  many- 
tiny  florets  in  a  flower  head.  A  large  proportion  of  our 
weeds  belong  to  this  family,  the  members  of  which  have 
many  advantages  in  the  struggle  for  existence. 

The  various  adaptations  for  the  dispersal  of  the  seeds  are 
among  the  important  advantages  of  the  composite  plants. 


6        FARM  FRIENDS  AND  FARM  FOES 

The  seedlike  fruits  of  some  are  furnished  with  a  fringe  or 
tuft  of  hairs  that  enables  them  to  be  carried  long  distances  by 
the  wind.  The  dandelions,  thistles,  goldenrods,  and  asters 
are  examples  of  these.  Many  others  are  provided  with 
some  device  for  becoming  attached  to  animals.  Burdocks, 
clotburs  and  Spanish  needles  are  examples  of  these. 
Still  others  have  hard  nutlike  fruits  that  are  able  to  float 
upon  running  water.  The  tall  ragweeds  and  the  common 
ragweeds  are  examples  of  these. 

It  is  easy  to  understand  why  the  roadsides  are  generally 
infested  with  many  of  the  composite  plants  whose  seed- 
like  fruits  or  akenes  are  blown  about  by  the  wind.  The 
open  road  furnishes  free  passage,  and  the  fences  along  its 
borders  catch  hosts  of  them  as  they  fly  along.  So  the 
goldenrods,  asters,  thistles,  and  various  sorts  of  wild  lettuce 
are  familiar  roadside  weeds.  These  are  mostly  native 
species  that  are  willing  to  live  and  let  live,  and  thus  do  not 
entirely  overrun  the  ground  as  do  such  imported  pests  as 
Prickly  Lettuce,  a  roadside  weed  which  has  attracted  much 
attention  during  recent  years.  It  apparently  was  first 
noticed  in  New  England  about  1868,  and  it  is  now  found 
over  a  large  part  of  the  United  States,  being  especially 
abundant  in  the  Middle  West. 

Prickly  Lettuce,  when  mature,  is  from  two  to  six 
feet  high,  with  a  straight  stalk  bearing  large  stemless 
leaves,  the  bases  of  which  clasp  the  main  stalk.  The 
flowers  are  borne  in  an  open  panicle  on  the  upper  end 
of  the  stalk,  each  blossom  being  small,  yellow,  and 
not  very  conspicuous.  The  first  flowers  appear  about 
midsummer,  and  others  continue  to  develop  until  au- 
tumn. The  leaves  and  stems  have  a  milky  juice  which 
is  doubtless  a  protection  from  insect  attack,  while  the 
numerous  prickles  over  the  surface  are  likewise  a  pro- 


WEEDS   OF   ROADSIDES   AND   WASTE   PLACES 


BURDOCK 


tection  from  the  attack  of  herbivorous  animals.  Many 
thousand  seeds  are  commonly  produced  by  a  single  plant, 
and  each  of  these  seeds  is  furnished  with  a  fine  pappus, 
so  that  it  may  be  carried  long  distances  by  the  wind. 

This  is  a  difficult  weed  to  keep  in  check.  It  occupies 
roadsides  and  waste  grounds  very  quickly,  and  its  seeds 
are  blown  from  such  situations  to  cultivated  fields.  The 
growing  of  hoed  crops  and  repeated  mow- 
ing of  patches  where  the  plant  is  es- 
tablished—  thus  preventing  seeding  — 
are  the  most  advisable  measures  of  pro- 
tection. 

Among  the  composite  plants  whose 
seeds  are  carried  by  animals,  the  Bur- 
dock is  perhaps  the  most  generally 
known.  Its  coarse  leaves  and  spiny  seed 
heads  are  to  be  found  in  many  neglected 
corners.  It  is  a  biennial,  making  a  vig- 
orous growth  of  leaves  near  the  ground 
during  the  first  season,  and  storing  in 
the  root  a  large  amount  of  nourishment  for  the  rapid  de- 
velopment of  the  great  flower  stalk  the  second  season. 
The  tiny  florets  are  crowded  together  in  composite  heads, 
having  a  pinkish  color,  and  surrounded  by  a  mass  of  bracts 
with  recurved  spiny  tips.  As  the  seeds  ripen,  these  spiny 
burs  become  brown  and  easily  break  away  to  be  carried  by 
any  animals  that  may  come  in  contact  with  them,  scattering 
the  seed  as  they  journey.  The  plants  vary  greatly  in  height 
according  to  the  richness  of  the  soil  in  which  they  grow. 
They  are  easily  pulled  up  when  quite  small,  but  the  second 
season  they  must  be  repeatedly  cut  off  below  the  soil  sur- 
face to  prevent  their  blossoming,  or  else  killed  by  pouring 
kerosene  or  some  other  suitable  liquid  upon  the  crown. 


FARM   FRIENDS   AND   FARM   FOES 


BUCKWHEAT  AND  PLANTAIN  FAMILIES 

The  most  familiar  members  of  the  Buckwheat  family  are 
the  sorrels,  docks,  and  smartweeds.  These  all  have  small 
flowers  and  the  triangular  akenes  characteristic  of  the 
family. 

Two  species  of  Dock  are  abundant  and  widely  distrib- 
uted weeds.  These  are  the  Curled  Dock,  Sour  Dock,  or 
Yellow  Dock,  and  the  Bitter  Dock  or 
Broad-leaved  Dock.  The  former  is 
easily  distinguished  by  its  comparatively 
narrow  curled  leaves.  The  Curled  Dock 
is  often  used  for  "  greens,"  but  the 
Broad-leaved  Dock  is  so  bitter  that  it  is 
not  used  for  this  purpose.  Both  of  these 
species  are  likely  to  be  troublesome  in 
wet  places  especially  along  the  roadsides 
and  fences,  and  can  be  eradicated  only 
by  extermination  of  the  roots.  These 
contain  so  much  stored-up  nutriment, 
that  if  the  plants  are  simply  pulled  up 
and  left  upon  the  surface  of  the  ground, 
the  seeds  often  mature ;  consequently 
it  is  better  to  burn  the  plants  or  at  least 
to  cut  the  stalk  away  from  the  roots. 

On  account  of  the  way  in  which  the  Broad-leaved  Plantain 
springs  up  wherever  civilized  man  appears,  the  American 
Indians  used  to  call  it  White  Man's  Foot.  It  is  the  most 
abundant  representative  of  the  Plantain  family,  though  in 
fields  of  grain  and  forage  crops  the  Narrow-leaved  Plantain 
is  more  troublesome. 

The  Broad-leaved  Plantain  is  a  sturdy,  vigorous  plant, 
well  adapted  to  crowding  out  others  in  the  struggle  for 


BROAD-LEAVED\\  DOCK 


WEEDS  OF  ROADSIDES  AND   WASTE  PLACES        9 

existence.  Its  roots  are  large  and  fibrous,  taking  firm  hold 
upon  the  soil ;  the  main  stem  is  so  short  as  not  to  appear 
above  the  ground ;  the  broad  flat  leaves  are  borne  on  the 
ends  of  long  stems,  forming  a  rosette  on  the  soil  surface, 
so  that  the  trampling  of  animals  does  not  injure  them.  The 
leaves  are  not  palatable  to  higher  animals  and  are  eaten 
by  very  few  insects. 

In  addition  to  these  advantages  the  small  inconspicuous 
flowers  are  borne  closely  along  the  sides  of  the  strong  and 
flexible  stalks,  upon  which  the  seeds  rapidly  develop. 
The  seeds  themselves  are  provided  with  a  mucilaginous 
covering,  which  when  wet  adheres  to  the  fur  of  animals  so 
that  they  are  likely  to  be  carried  in  many  directions. 

The  Plantain  is  especially  likely  to  take  possession  of 
waste  corners  of  the  premises,  as  well  as  neglected  places 
along  roadsides.  In  lawns  it  is  a  vexatious  pest,  requiring 
constant  attention  to  keep  it  out.  The  use  of  a  sharp- 
pointed  hoe  which  will  cut  off  the  plant  below  the  surface 
is  an  effective  remedy.  During  wet  weather,  the  smaller 
seedlings  may  readily  be  pulled  up  by  hand. 

WEEDS  OF  OTHER  FAMILIES 

Three  common  wayside  weeds  belong  to  the  Evening 
Primrose  family  —  Fireweed  or  Willow-herb,  Evening 
Primrose,  and  Sundrops.  The  first  named  often  springs 
up  where  a  fire  has  left  a  lot  of  ashes  for  the  seeds  to 
sprout  in.  It  is  seldom  really  troublesome  in  cultivated 
land,  although  its  winged  seeds  must  be  scattered  every- 
where. 

The  Evening  Primrose  is  one  of  the  most  abundant 
roadside  plants.  It  is  especially  likely  to  take  possession 
of  sloping  banks  and  thrives  either  in  open  sunlight  or  in 
partial  shade.  Under  favorable  conditions  it  grows  to  a 


10 


FARM  FRIENDS  AND  FARM  FOES 


height  of  several  feet  and  produces  in  its  curious  capsules 
vast  numbers  of  the  tiny  seeds,  which  may  be  blown  long 
distances  by  violent  winds.  It  may  be  suc- 
cessfully kept  in  check  by  repeated  mowings 
close  to  the  ground. 

The  little  plant  called  Sundrops  seems  like 
the  Evening  Primrose  in  miniature.  It  is 
often  abundant  along  roadsides,  and  fre- 
quently spreads  to  adjacent  fields,  where  it  is 
especially  troublesome  in  broadcasted  grain 
and  forage  crops.  Thorough  tillage  in  corn, 
cabbage,  or  some  other  hoed  crop  is  the  best 
way  to  rid  a  field  of  it. 

A  great  variety  of  other  plants  are  likely 
to  appear  as  more  or  less  noxious  weeds  along 
roadsides.  Familiar  examples  in  many  of  the 
states  are  found  in  Teasel,  Elecampane,  and 
Butter-and-Eggs.  Each  of  these  may  occa- 
sionally become  troublesome  in  cultivated  fields  if  left  un- 
molested along  the  roadsides,  but  they  are  comparatively 
easy  to  keep  in  check  by  attention  at  the  proper  season. 

Some  common  roadside  weeds  have  escaped  from  culti- 
vation. The  majority  of  these  are  likely  to  be  plants 
formerly  grown  in  flower  gardens,  although  most  of  them 
are  now  displaced  by  more  attractive  flowers.  Throughout 
New  England,  the  pinkish  blossoms  of  Bouncing  Bet,  or 
Soapwort,  are  likely  to  be  seen  along  the  roadside  near 
an  abandoned  homestead.  In  early  times  this  plant  evi- 
dently was  a  garden  favorite  and  it  remains  along  the 
roadside,  though  it  seldom  becomes  really  troublesome 
as  a  weed. 

In  a  similar  way,  the  curious  Cypress  Spurge,  the  Day 
Lily,  and  the  Live-forever  are  commonly  seen  along  the 


WEEDS  OF  ROADSIDES  AND  WASTE  PLACES      u 


roadsides,  to  which  they  have  escaped  from  gardens. 
They  are  usually  present  in  solid  patches,  which  are  to  be 
cleared  away  only  by  thorough  digging  of  all  the  roots. 
As  a  rule  these  are  not  likely  to  go  so  far  afield  or  prove 
so  troublesome  as  certain  of  the  aromatic  herbs  that 
were  formerly  cultivated.  Of  the  latter  Yarrow,  Tansy, 
and  Caraway  are  commonly  most  injurious.  The  seeds 
of  these  may  be  scattered  by  the  wind  over  considerable 
areas.  Consequently  it  is  very 
desirable  that  the  small  plants 
be  destroyed  as  soon  as  pos- 
sible. 

Even  some  of  the  plants  in 
the  vegetable  garden  may  at 
times  escape  from  cultivation 
and  become  troublesome.  The 
most  notable  illustrations  of 
this  are  found  in  Horse-radish, 
Chicory,  and  Salsify  or  Vege- 
table Oyster.  The  first  named 
reproduces  only  by  vegetative 
roots  ;  but  Chicory  and  Salsify 
produce  seeds  that  scatter  in 
all  directions,  coming  up  as 
weeds  in  situations  favorable 
to  growth. 

Not  all  of  the  plants,  how- 
ever, which  are  likely  to  take 
possession  of  neglected  bits  of  ground  are  to  be  classed 
as  wholly  noxious.  For  example  the  Sweet  Clovers  are 
among  the  most  abundant  occupants  of  such  soil,  crowding 
out  other  plants  and  developing  a  thrifty  growth  of  leaves 
and  blossoms.  The  blossoms  are  a  valuable  source  of 


TOADFLAX  OR  BUTTER-AND-EGGS 


12       FARM  FRIENDS  AND  FARM  FOES 

nectar  for  honey  bees,  and  the  roots  of  these  clovers  im- 
prove the  condition  of  the  soil  by  adding  to  its  store  of 
nitrogen  and  organic  matter.  It  is  doubtful  whether  in  the 
case  of  many  bits  of  waste  land  occupied  by  these  plants 
it  is  worth  while  to  attempt  to  exterminate  them.  When 
they  grow  along  alfalfa  or  other  fields  in  which  they  are 
harmful,  however,  they  should  of  course  be  destroyed. 

OBSERVATIONS   FOR  PUPILS 

1.  Make  a  list  of  twelve  common  roadside  weeds  in  your  locality. 

2.  Make  drawings  of  as  many  of  these  as  you  can  to  use  in  your 
Booklet  on  Weeds.     For  this  booklet  print  an  attractive  title-page. 
Perhaps  the  one  on  p.  29  will  help  you  in  doing  this. 

3.  Press  and  mount  some  of  the  leaves  and  flowers  of  the  roadside 
weeds  to  bind  up  in  your  booklet. 

4.  Make  a  list  with  this  heading  at  the  top  of  the  page  : 

Roadside  Weeds  I  have  seen  in  Neighboring  Fields 

5.  Find  out  how  the  seeds  of  roadside  weeds  are  scattered.     Make 
lists  with  these  headings  : 

Seeds  scattered  by  the  Wind 
Seeds  scattered  by  Water 
Seeds  scattered  by  Animals 

6.  Always  watch  for  new  roadside  weeds.     When  one  appears,  send 
a  specimen  to  your  State  Experiment  Station  to  learn  its  name.     Here 
is  the  sort  of  a  letter  you  should  send : 

— ,  KANSAS, 
September  21,  1911. 
EXPERIMENT  STATION, 

MANHATTAN,  KANSAS. 

Gentlemen  :  I  am  sending  you  by  this  mail  in  a  package 
securely  packed  a  plant  I  found  by  the  roadside  near  our 
school.  We  do  not  know  its  name  and  we  shall  be  greatly 
obliged  if  you  will  inform  me  what  it  is  and  whether  it  is 
likely  to  become  a  troublesome  weed. 
Sincerely  yours, 

JAMES  A.  SMITH. 


CHAPTER   II 


The  Weeds  of  Meadows  and  Pastures 

THE  weeds  of  meadows  and  pastures  that  have  been  in 
sod  for  many  years  are  likely  to  be  native  species   that 
appear  to  be  trying  to  bring  the  fields  back  to  the  original 
condition  of  the  untilled  land.     In  a  for- 
est region,  the  land  will  revert  to  forest ; 
in  a  plains  region,  it  will  revert  to  plains. 
This  is  the  natural  result  of  neglect  on 
the  part  of  the  farmer ;  nature  is  claim- 
ing her  own. 

The  ways  in  which  these  fields  are 
brought  back  to  the  wild  condition  are 
well  worth  studying.  Go  to  such  a  neg- 
lected pasture  and  notice  how  shrubs 
and  vines  spring  up  along  the  sides  of 
fences,  where  seeds  have  been  blown 
by  winds  or  left  by  birds.  Notice  how 
these  spread  outward  by  means  of  seeds 
and  rootstocks.  See  how  the  untilled, 
unfertilized  sod  is  "run  out,"  and  re- 
placed by  mosses  or  ferns  or  other  weedy  growths,  and 
how  the  seeds  of  Hardback,  Sweet-fern,  and  other  plants 
begin  to  grow  in  the  moss.  Then  see  how  these  low  bushes 
form  a  suitable  shelter  for  poplars,  birches,  and  other  trees 
to  start,  and  how  these  in  turn  may  shade  the  ground  for 
the  early  growth  of  larger  trees. 

In  the  plains  regions  the  plants  will  be  different,  but  the 

13 


MILKWEED  PODS 


14       FARM  FRIENDS  AND  FARM  FOES 

process  of  encroachment  from  the  neighboring  species  will 
be  much  the  same.  In  pastures  where  the  native  grasses 
form  the  chief  forage,  a  frequent  cause  of  weed  invasion 
is  found  in  keeping  too  many  animals  in  the  fields.  These 
feed  so  closely  that  the  grasses  are  killed  out,  and  other 
plants  not  eaten  by  the  stock  take  their  places. 

On  the  other  hand,  many  meadows  have  problems  of 
their  own.  This  is  most  likely  to  result  from  a  mixture  of 
the  seeds  of  some  weed  with  that  of  the  grass,  clover,  or 
grain,  or  it  may  be  through  the  seeds  in  the  fertilizers  from 
the  barn.  Sometimes  these  may  be  weeds  new  to  the  lo- 
cality, and  it  is  then  very  important  to  exterminate  them 
before  they  scatter  seed. 

TROUBLESOME  GRASSES 

A  number  of  grasses  more  or  less  valuable  for  forage 
often  prove  difficult  to  eradicate  in  meadows  and  pastures 
where  they  crowd  out  more  valuable  sorts.  They  are 
able  to  displace  other  plants  because  they  spread  by  creep- 
ing underground  rootstocks  that  take  complete  possession 

of  the  soil  in  all  directions.  One 
of  the  worst  of  these  is  the 
notorious  Witch-grass,  Quack- 
grass,  or  Couch-grass.  In  lo- 
calities where  Johnson-grass  has 
been  introduced  for  forage,  this 
is  likely  to  prove  as  troublesome. 
Wire-grass  or  Flat-stemmed 
Blue-grass  is  another  species 
that  is  likely  to  take  possession 
SPRIG  OF  JOHNSON-GRASS  of  jight  sandy  soiL 

All  these  troublesome  grasses  are  likely  to  be  introduced, 
either  with  barnyard  fertilizers  or  with  grass  and  grain 


WEEDS  OF  MEADOWS  AND   PASTURES  15 

seeds.  In  permanent  pastures  some  patches  may  be  kept 
down  by  salting,  thus  inducing  close  feeding  by  sheep  or 
cattle.  In  some  cases,  however,  the  removal  of  the  turf 
or  cultivation  with  a  hoed  crop  becomes  necessary. 

Most  meadow  and  pasture  weeds  are  troublesome,  be- 
cause they  reduce  the  product  of  the  land,  but  the  Squirrel- 
tail  Grass  or  Tickle-grass  is  much  worse 
than  these,  because  it  produces  festering 
sores  in  the  mouths  of  cattle.  Consequently 
it  not  only  reduces  the  grass  and  hay  crop, 
but  it  renders  them  of  less  value  for  feeding. 
This  is  a  widely  distributed  annual,  easily 
recognized  by  its  glistening,  whitish  heads 
of  barbed  awns,  each  awn  an  inch  or  two 
in  length.  It  is  especially  troublesome  in 
Western  meadows  and  alfalfa  fields,  being 
considered  in  many  regions  the  most  pes- 
tiferous weed.  The  seeds  are  carried  by  the 
wind,  though  fortunately  they  are  not  dis- 
tributed in  grass  seed.  Rotation  with  an 
annual  crop,  or  the  pulling  and  burning  of 
the  plants  before  the  heads  appear  are  the 
only  effective  remedies,  and  they  necessitate 
community  action  for  the  best  results.  If 
one  farmer  keeps  his  meadows  free  and  his 
neighbor  does  not,  there  is  little  benefit  to 
either. 

In  California  a  closely  related  annual  grass  from  Europe 
is  troublesome  in  similar  ways.  It  is  called  Mouse  Barley 
or  Wild  Barley,  and  is  often  abundant  in  sandy  pas- 
tures. 


i6 


FARM   FRIENDS  AND   FARM  FOES 


SUNFLOWER  FAMILY 

Meadows  and  pastures  that  have  been  seeded  for  a  long 
time  are  liable  to  become  infested  by  a  number  of  vigorous 
weeds  of  the  great  Sunflower  or  Thistle  family  (Composite^ 
some  of  which  prove  exceedingly  troublesome  unless  they 
are  carefully  eradicated  on  their  first  appearance.  One  of 
the  most  conspicuous  of  these  is  the  Oxeye 
Daisy  or  Whiteweed.  In  many  of  the  New 
England  and  Middle  states  whole  fields  are 
whitened  by  it  in  early  summer.  The 
blossoms  are  beautiful,  but  their  beauty  is 
not  likely  to  be  appreciated  by  the  farmer 
who  sees  them  take  the  place  of  a  good 
crop  of  hay.  The  plant  is  so  distinctive 
on  account  of  the  character  of  the  blos- 
soms, with  their  large  yellow  centers  sur- 
rounded by  rays  of  long  white  petals,  that 
it  is  at  once  recognized  by  every  one.  The 
flowers  are  borne  on  stems  one  to  two  feet 
high,  several  of  the  stems  generally  devel- 
oping from  a  single  root. 
CONE-FLOWER  jt  js  easv  to  see  why  the  Qxeye  Daisy 

is  a  dangerous  intruder  in  meadow  lands.  Its  period  of 
blossoming  extends  from  May  to  November,  so  that  it  is 
able  to  ripen  an  enormous  number  of  seeds.  These  are 
readily  scattered  and  soon  develop  into  little  plants  that 
are  rarely  noticed  the  first  season.  They  blossom  quickly 
the  second  season,  and  continue  as  perennials  thereafter. 
Each  plant  spreads  out  to  form  new  crowns,  and  thus  crowds 
out  the  surrounding  grasses.  The  fresh  leaves,  stems,  and 
flowers  are  distasteful  to  cattle,  and  very  few  insects  will 
eat  any  part  of  the  plant. 


WEEDS   OF   MEADOWS  AND   PASTURES  17 

The  careful  pulling  of  these  daisies  in  meadows  or  pas- 
tures when  they  first  appear  and  before  they  have  gone  to 
seed,  will  help  greatly  in  keeping  them  out.  In  general, 
frequent  rotation  of  crops  with  good  cultivation  and  fer- 
tilization is  useful  in  preventing  the  growth  of  this  as  well 
as  of  other  weeds. 

The  Orange  Hawkweed  is  another  dangerous  weed  of 
this  family  introduced  from  Europe.  Although  the  date 
of  its  appearance  on  American  soil  is  comparatively  recent, 
it  has  spread  over  a  large  part  of  the  country,  and  in 
many  places  .has  already  become  seriously  troublesome. 
It  has  a  dozen  or  more  medium-sized  orange-colored 
blossoms  borne  on  the  top  of  a  hairy  stem,  a  foot  or  more 
high.  Nearly  all  the  oblong  leaves  are  in  a  rosette  at  the 
base  of  the  flower  stalk ;  they  are  hairy  and  about  four 
inches  long.  The  plant  lives  from  year  to  year  by  means 
of  its  rootstocks  and  runners  that  spread  from  a  single 
root  in  all  directions. 

The  Orange  Hawkweed  is  most  likely  to  appear  in  pas- 
tures or  meadow  lands,  and  should  be  destroyed  by  a  thick 
layer  of  salt  as  soon  as  noticed.  When  large  areas  are  in- 
fested, the  application  of  salt  at  the  rate  of  a  ton  to  the 
acre  is  recommended. 

The  spiny  leaves,  stems,  and  purple  flower  heads  of  the 
common  Pasture  Thistle  are  familiar  to  every  one.  This 
plant  is  a  biennial.  When  one  of  the  winged  seeds  lodges 
in  a  bit  of  soil,  it  develops  the  first  season  into  a  rosette  of 
leaves  that  store  up  nutriment  in  the  thickened  taproot. 
This  rosette  lives  through  the  winter  and  the  next  season 
sends  up  the  spiny  flower  stalk  to  develop  a  new  crop 
of  seeds.  Fortunately  the  plant  spreads  only  through  the 
seeds  and  is  easily  destroyed  by  cutting  off  below  the 
crown. 


i8 


FARM  FRIENDS  AND   FARM  FOES 


The  Canada  Thistle  is  distinguished  from  the  common 
pasture  thistle  by  its  small  flower  heads.     The  plant,  as  a 
whole,  is  more  slender,  while  its  leaves  are  narrower  and 
more  deeply  cut.    The  flowers  are  purple, 
and  are  followed  by  seeds  bearing  a  feath- 
ery pappus.     The  species  is  regarded  as  one 
of  the  most  troublesome  weeds,  largely  on 
account  of  its  perennial  roots  which  spread 
in  all  directions,  so  that  a  single  plant  may 
become  a  center  from  which  many  others 
develop.     Because  of  these  roots,  also,  the 
plant  is  difficult  to  eradicate.      Thorough 
plowing,  repeated  mowing, 
seeding  down  to  get  a  heavy 
sod,  and  the  application  of 
kerosene  to  the  roots  are 
the  remedies  most  gener- 
ally recommended. 

When    tillable    land    is 
badly  infested  with  Canada 
Thistles  the  following  pro- 
cedure is  recommended  by 
the  Illinois  Experiment  Station  :  — 

1.  Cut  the  thistles  when  in  full  bloom  (July)  as  close  to 

the  ground  as  possible. 

2.  Plow  about  three   inches   deep    and   sow   millet   or 

Hungarian  grass,  seeding  heavily ;  harrow.  This 
may  follow  the  preceding  at  once  or  after  some 
two  weeks'  delay. 

3.  In  September  plow  under  the  crop,  or  save  it  for  hay, 

as  desired.  At  all  events,  plow  and  seed  liberally 
with  rye. 


WEEDS  OF  MEADOWS  AND   PASTURES  19 

4.  Plow  under  rye  in  May  and  seed  again  with  millet, 

or  Hungarian  grass,  or  plant  to  some  hoed  crop 
(corn)  and  give  the  most  thorough  cultivation, 
with  continued  destruction  of  every  remaining 
thistle. 

5.  Continue  the  clean  cultivation  and  sharp  lookout  for 

thistles  another  year. 

The  Cone-flower,  the  Flea-banes  or  White-tops  and  the 
various  sorts  of  Wild  Sunflowers  are  well-known  plants 
that  are  frequently  troublesome  in  meadows  and  pastures. 
They  generally  make  a  tall  and  vigorous  growth  that 
shades  the  grass  beneath,  and  thus  prevents  its  develop- 
ment. When  they  take  possession,  tillage  and  reseeding 
are  necessary. 

The  Chondrilla,  a  curious  European  plant  compara- 
tively recently  introduced,  proves  troublesome  in  pastures 
with  light  soils.  It  is  a  biennial,  developing  during  the 
first  season  low-lying  rosettes  of  leaves,  very  similar  to 
those  of  the  dandelion.  On  these  the  small  yellow  com- 
posite flowers  appear,  to  develop  later  into  seed  fruits, 
which  also  are  strikingly  like  those  of  the  dandelion.  They 
are  scattered  by  the  wind,  so  that  when  once  introduced 
into  a  new  locality  the  Chondrilla  is  likely  soon  to  be  gen- 
erally distributed.  Cultivation  and  fertilization  seem  to  be 
the  best  measures  to  exterminate  it. 

Several  trouble  makers  in  lowland  pastures  are  those 
weedy  composite  plants  having  spiny  or  hooked  fruits  that 
become  attached  to  the  wool  of  sheep  or  the  hair  of  other 
animals.  The  Spanish  Needles,  Bur  Marigolds,  Beggar 
Ticks,  and  Stick-tights  are  examples  of  these.  Such  plants 
are  likely  to  develop  in  undrained  areas,  and  proper  drain- 
age is  generally  necessary  to  check  their  increase.  Along 


20       FARM  FRIENDS  AND  FARM  FOES 

the  margins  of  streams  frequent  mowing  through  the  sea- 
son will  prove  helpful. 

The  Blue  and  the  White  Vervains  or  Wild  Verbenas, 
Ironweed,  Joe-pye  weed,  and  fhe  various  Wild  Asters  are 
other  well-known  plants  of  this  family  that  are  likely  to  be 
abundant  in  moist  places  in  pastures  and  meadows.  Drain- 
age, tillage,  and  seeding  down  are  the  best  ways  to  be  rid 
of  them. 

CARROT  FAMILY 

The  Wild  Carrot,  which  is  typical  of  the  great  family  of 
umbel-bearing  plants,  is  particularly  troublesome  in  pastures 
and  meadows.  Such  fields  are  often  wholly  occupied  by 
it,  rendering  the  little  grass  that  may  develop  practically 
worthless.  This  plant  has  been  troublesome  in  the  Eastern 
states  for  many  years,  and  has  recently  been  spreading 
through  the  fertile  fields  of  the  Middle  West. 

The  small  white  flowers  of  the  Wild  Carrot  are  crowded 
together  in  flat  conspicuous  heads,  commonly  having  a 
little  purple  flower  in  the  middle.  These  develop  into 
curious  masses,  suggesting  miniature  birds'  nests,  rounded 
in  outline.  The  individual  "  seeds "  are  really  spinose 
akenes  which  may  be  distributed  by  animals  or  by  the  wind 
that  blows  the  whole  seed  head  along  when  it  breaks  off. 

The  Wild  Carrot  propagates  only  by  means  of  seeds,  so 
that  the  main  point  to  be  attained  in  suppressing  it  is  the 
prevention  of  seeding.  This  may  be  accomplished  by  per- 
sistent mowing,  which  will  finally  lead  to  the  death  of  the 
plants.  At  first,  mowing  simply  causes  new  flower-bear- 
ing shoots  to  be  sent  out.  The  plants  may  also  be  de- 
stroyed by  hand  pulling,  or  by  cutting  them  off  slightly 
below  the  soil  surface  with  a  spud,  hoe,  or  disk  harrow. 
When  a  grass  field  is  badly  infested  with  this  weed,  the 


WEEDS   OF   MEADOWS   AND   PASTURES 


21 


best  way  of  treating  it  generally  is  to  plow  and  plant  with 
cultivated  crops  for  a  time. 

In  the  states  bordering  on  the  Gulf  of  Mexico  another 
species  of  Wild  Carrot  is  very  troublesome.  It  is  called 
the  Small  Carrot.  It  is  a  biennial,  occurring  in  all  sorts 
of  situations  to  which  the  seeds  may  be  carried  by  wind  or 
animals. 

OTHER  HERBACEOUS  WEEDS 

Two  members  of  the  Plantain  family  are  often  trouble- 
some in  meadows  and  pastures.  The  Western  or  Large- 
bracted  Plantain  ap- 
pears to  have  been 
originally  native  to 
the  Mississippi  Val- 
ley, but  has  recently 
become  very  gener- 
ally  distributed  in 
grass  and  clover 
seed.  It  is  com- 
monly classed  as 
a  winter  annual, 
though  it  may  also 
develop  from  seeds 
scattered  in  spring. 
It  differs  from  the 
other  plantains  in 
its  plume-like  flower 
heads,  due  to  a  large 

bract    projecting  MILKWEED  SEEDS 

from  beneath  each 

tiny  floret  on  the  spike.      The  leaves  are  short  and  narrow 
so  that  the  plants  do  not  become  conspicuous   until  the 


22 


FARM  FRIENDS  AND  FARM  FOES 


flower  heads  appear.  A  single  plant  may  produce  three 
thousand  seeds  which  are  likely  to  be  carried  but  a  short 
distance.  Consequently  a  dense  colony  will  soon  be  pres- 
ent, crowding  out  all  other  vegetation.  Pulling  the  plants, 
frequent  mowing,  or  tillage  in  a  hoed  crop  seem  to  be  the 
only  remedial  methods.  The  sowing  of  pure  grass  and 
clover  seed  is  the  most  important  preventive  measure. 

The  Ribwort,  Rib-grass,  or  Narrow-leaved  Plantain  is  one 
of  the  most  trying  pests  that  infest  light  soils.  It  is  com- 
monly introduced  in  clover  and  grass  seed  and  soon  de- 
velops a  thickened  rootstock  that  renders  it  very  difficult 
to  eradicate.  On  account  of  this  rootstock  it  is  a  peren- 
nial, so  that  the  mere  prevention  of  seeding  will  not  lead 
to  extermination ;  the  roots  must  be  pulled  up,  cut  off 

deeply,  or  plowed  under. 

On  barren  sandy  lands 
in  meadows  and  pastures 
as  well  as  in  cultivated 
fields,  the  Sheep  Sorrel  or 
Field  Sorrel  is  likely  to  take 
complete  possession  of  the 
soil.  This  well-known  weed 
is  an  indication  of  poor 
farming,  and  the  best  way 
to  eradicate  it  is  to  enrich 
and  till  the  infested  areas. 
Its  seed  is  very  commonly 
distributed  in  barnyard  fer- 
tilizers, as  well  as  in  other 
ways,  and  the  plant  is  likely 
to  appear  in  any  neglected 

spot  where  the  soil  is  acid.  It  is  so  easily  eradicated 
by  good  methods  of  farming  that  it  need  never  become 


bHEEP  bORREL 


WEEDS  OF   MEADOWS  AND   PASTURES  23 

troublesome.  Its  presence  indicates  that  lime  should  be 
applied. 

Another  group  of  plants  that  are  likely  to  run  out  the 
grass  in  light  soils  in  dry  situations  is  that  of  the  Five- 
fingers  or  Cinquefoils  of  the  great  Rose  family.  The  Com- 
mon Cinquefoil,  the  Silvery  Cinquefoil,  and  the  Norwegian 
Cinquefoil  are  the  most  abundant  species.  The  Barren 
Strawberry  is  closely  associated  with  these  in  structure  and 
habit  of  growth,  and  is  often  found  in  the  same  situations. 
The  Cinquefoils  have  compound  leaves  composed  of  five 
leaflets,  while  the  leaves  of  the  Barren  Strawberry  are  com- 
posed of  but  three  leaflets.  Like  the  common  Wild  Straw- 
berry all  these  plants  occupy  increasing  areas  by  send- 
ing out  runners  just  above  the  surface  of  the  ground,  the 
runners  starting  new  plants  that  take  root  and  in  turn 
send  out  other  runners.  In  this  way  the  soil  is  soon 
covered  with  a  mat  of  plants  that  prevents  the  growth  of 
grasses. 

These  low-growing  weedy  plants  often  furnish  favorable 
conditions  of  shade  and  moisture  for  the  starting  of  larger 
species  like  the  St.  Johnsworts  and  the  Goldenrods.  There 
are  various  kinds  of  each  of  these,  some  of  which  often 
render  hilly  pastures  yellow  with  their  bloom.  Along  with 
them  are  likely  to  occur  the  white  blossoms  of  the  Yarrow 
and  the  small  flower  heads  of  the  Wild  Asters. 

The  presence  of  most  of  these  weeds  in  light  soils  is  an 
indication  of  the  need  of  soil  improvement  by  tillage  and 
fertilization. 

Various  kinds  of  Milkweeds,  especially  the  Common 
Milkweed,  are  likely  to  prove  troublesome  in  pastures  and 
meadows.  Such  plants  send  out  underground  rootstocks 
in  all  directions  ;  from  these,  vigorous  new  shoots  come  up 
so  that  a  strong  colony  is  soon  spreading  outward  to  shade 


FARM   FRIENDS   AND   FARM   FOES 


and  destroy  the  grass.  The  winged  seeds  are  scattered 
everywhere;  consequently  it  is  very  desirable  to  extermi- 
nate wayside  plants. 

Several  species  of  Buttercups  abound  in  lowland  meadows 
and  pastures.  When  green  some  of  the  more  abundant  of 
these  have  an  acrid  taste  that  leads  cattle  to  pass  them  by, 
though  this  bitterness  is  •  so  lost  in  drying  that  the  hay  is 
not  especially  injured. 

FERNS  OUT  OF  PLACE 

In  the  more  northern  regions  of  our  land  various  species 
of  ferns  often  take  possession  of  parts  of  meadows  and 
pastures.  They  are  likely  to  start 
along  a  hedge,  fence,  or  the  borders 
of  the  woods,  and  gradually  to  ex- 
tend over  a  greater  area.  The 
Brake  Fern,  or  Bracken,  is  one  of 
the  most  abundant  of  these.  It  is 
especially  liable  to  overrun  com- 
paratively dry  land  in  the  open 
sunshine,  while  most  of  the  other 
ferns  are  more  likely  to  overrun 
moist  or  shaded  parts  of  a  field. 
The  Sensitive  Fern,  the  Cinnamon 
Fern,  and  the  Flowering  or  Inter- 
rupted Fern  are  often  troublesome 
in  undrained  spots.  All  these 
ferns,  however,  are  symptoms  of 
lack  of  drainage  or  neglect  of  til- 
lage, and  are  to  be  subdued  by  im- 
proved agricultural  methods.  Their  destruction  when  they 
have  full  possession  of  the  soil  is  a  difficult  matter,  requir- 
ing frequent  hoeing  and  cultivating  for  several  seasons. 


HARDBACK 


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CAPSULE 

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WEEDS  OF  MEADOWS  AND   PASTURES  25 

TROUBLESOME  TREES  AND  SHRUBS 
Over  a  great  central  region  in  the  United  States  the 
Sassafras  is  a  troublesome  fence-side  bush.  Its  seeds  are 
carried  by  birds,  and  its  underground  rootstocks  spread  out 
to  form  a  thicket  of  new  plants.  In  the  latter  respect,  it 
resembles  the  Yellow  or  Black  Locust,  though  the  seeds 
of  this  tree  are  scattered  by  the  wind.  When  Locust 
thickets  are  once  established  in  a  pasture  or  meadow,  they 
are  difficult  to  eradicate.  Their  presence,  however,  is  not 
so  dangerous  as  that  of  the  Honey  Locust,  for  the  great 
thorns  of  this  tree  sometimes  penetrate  the  feet  of  cattle 
and  cause  much  trouble. 

Many  other  trees  and  shrubs  are  liable  to  prove  trouble- 
some in  pastures  and  meadows  if  permitted  to  establish 
themselves  along  walls  and  fences.  The  surest  way  to 
prevent  their  spreading  is  to  cut  them  off  as  fast  as  they 
appear,  cutting  persistently  every  year,  especially  in  sum- 
mer when  the  new  growth  is  finished.  It  is,  of  course,  de- 
sirable to  do  away  with  all  needless  fences. 

Many  kinds  of  shrubs  and  trees  are  likely  to  take  posses- 
sion of  neglected  pastures,  especially  in  hilly  regions. 
In  northern  localities  the  Gray  Birch  and  the  Aspen 
Poplar  spring  up  in  great  abundance,  as  do  also  the  Low 
Juniper  and  the  Red  Cedar  or  Savin.  The  latter  are 
especially  likely  to  arise  in  clumps  of  Sweet-fern  or  Hard- 
hack.  These  are  two  of  the  most  troublesome  pasture 
shrubs.  The  easiest  way  to  keep  a  permanent  pasture  free 
from  such  intruders  is  to  exterminate  them  as  fast  as  they 
appear,  before  they  have  obtained  a  firm  foothold. 

POISONOUS  PASTURE  WEEDS 

The  most  vexatious  meadow  and  pasture  weeds  are  those 
that  not  only  prevent  the  growth  of  grasses,  but  are 


26       FARM  FRIENDS  AND  FARM  FOES 

poisonous  to  stock  when  eaten.  Several  such  pests  have 
proved  very  troublesome  in  the  United  States,  especially 
in  the  West,  although  they  are  by  no  means  restricted  to 
any  one  region. 

The  Loco  Weeds  are  the  most  notorious  of  the  stock- 
poisoning  herbs;  they  are  so-called  because  the  affected 
animals  become  "  locoed,"  the  Spanish  word  for  crazy. 
Several  species  are  known,  all  belonging  to  the  genus 
Astragalus,  of  the  great  family  of  Legumes  or  pod -bearing 
plants.  Peas,  beans,  and  vetches  are  familiar  examples  of 
the  legume  family.  Two  species  of  Loco  Weeds  are  the 
most  important :  one  is  called  the  Woolly  Loco  Weed  ; 
the  other  the  Stemless  Loco  Weed.  Both  are  sometimes 
called  Crazy  Weed. 

The  Woolly  Loco  Weed  is  a  perennial  plant  having  a 
general  resemblance  to  a  Vetch  or 
Larkspur.  Its  leaves  and  stems 
are  covered  with  silky  hairs  that 
give  it  a  silvery  effect,  and  its  pur- 
ple flowers  develop  into  two-celled 
seed-pods.  Leafstalks  and  flower 
stalks  arise  from  a  short  central 
stem.  The  plant  belongs  origi- 
nally to  a  wide  area  in  the  Great 
Plains  region,  between  Wyoming 
and  Texas,  though  especially 
troublesome  in  Colorado,  Nebraska, 
and  Kansas.  In  Colorado,  it  was 
so  destructive  that  bounties  were 
offered  for  its  destruction.  In 

four  years  nearly   $200,000  was 
POISON  HEMLOCK 

paid  by  the  state  for  this  purpose. 

The  Stemless  Loco  Weed  has  a  more  slender  appearance 


WEEDS  OF   MEADOWS  AND   PASTURES  27 

than  the  Woolly  species.  Its  leaflets  are  more  slender  and 
its  pods  are  one-celled.  It  is  distributed  over  an  even 
greater  area  than  the  Woolly  Loco  Weed. 

The  Larkspurs  are  closely  related  to  the  Loco  Weeds, 
belonging  to  the  same  family  of  Legumes.  There  are 
many  species  of  these,  several  of  which  are  known  to  be 
poisonous  to  stock.  The  Dwarf  Larkspur,  the  Purple 
Larkspur,  and  the  Wyoming  Larkspur  are  the  most  trouble- 
some kinds.  They  are  especially  likely  to  be  eaten  in  early 
spring,  when  the  leaves  offer  tempting  forage  to  cattle,  be- 
fore the  better  plants  are  well  started. 

Another  weed  that  has  been  very  troublesome  in  poison- 
ing stock  is  the  Rattlebox  or  Rattleweed.  This  is  native 
to  a  great  region  extending  from  New  Jersey  to  Kansas 
and  Minnesota,  occurring  especially  in  low  sandy  soils.  It 
is  dangerous  to  horses  and  cattle,  both  in  the  pastures  and 
in  hay.  In  some  of  the  Western  states  disease  in  horses 
caused  by  it  is  called  the  Bottom  Disease,  because  only 
stock  pasturing  on  the  so-called  bottom  lands  are  likely  to 
be  affected  by  it. 

A  few  poisonous  weeds  commonly  occur  in  wet  places  in 
meadows  and  pastures.  Thus  the  well-known  Sneezeweed 
with  its  attractive  yellow  flowers  is  poisonous  to  cattle,  sheep, 
and  horses.  It  is  abundant  along  ditches  and  the  borders 
of  ponds  and  streams.  The  Poison  Hemlock  or  Spotted 
Cowbane,  which  occurs  in  similar  situations,  is  even  more 
dangerous.  Not  only  are  all  parts  of  the  plant  extremely 
poisonous  to  man  and  animals,"  but  water  in  which  the 
roots  have  been  trampled  may  prove  poisonous.  The 
roots  have  an  aromatic  taste  that  leads  children  to  eat 
them,  sometimes  with  fatal  results.  Both  these  plants 
should  be  exterminated  wherever  they  occur. 

In  the  case  of  all  these  poisonous  weeds  the  only  safety 


28 


FARM  FRIENDS  AND  FARM  FOES 


lies  in  exterminating  them  to  as  great  an  extent  as  possible. 
And  it  is  especially  important  that  there  be  cooperation  to 
this  end  among  all  the  landowners  of  a  locality. 


POISON  IVY 


POISONOUS  TREES  AND  SHRUBS 

The  Choke  Cherry  is  one  of  the  commonest  and  most 
dangerous  of  shrubs.  It  is  found  along  roadsides,  woods 
and  fences,  throughout  the  greater  part  of  Canada  and  the 

United  States.  Its  seeds  are 
scattered  everywhere  by  birds, 
and  it  spreads  rapidly  by  un- 
derground stems.  As  the  leaves 
wilt  after  the  bushes  are  cut, 
Prussic  acid,  a  virulent  poison, 
is  formed  within  them  by  the 
combination  of  two  nonpoison- 
ous  substances.  This  is  often 
fatal  to  cattle  that  feed  upon 
the  withering  branches.  Conse- 
quently it  is  desirable  to  prevent  the  growth  of  Choke 
Cherry  bushes,  and  to  leave  no  freshly  cut  leaf-bearing 
branches  within  the  reach  of  stock. 

Black  Cherry  leaves  also  develop  this  poison  as  they 
wither,  and  perhaps  the  same  is  true  of  other  wild  cherries. 
,  Certain  species  of  Laurel,  especially  the  Mountain  Laurel 
and  Sheep  Laurel  or  Lamb-kill,  are  poisonous  to  stock. 
The  leaves  and  green  stems  contain  a  principle  that  is  even 
more  fatal  than  strychnine. 

Among  the  more  important  shrubs  that  are  likely  to 
spread  from  walls  and  fences  into  the  adjacent  fields  are 
the  various  species  of  Sumachs.  The  seeds  of  these  are 
left  along  fences  by  birds,  and  the  resulting  plants,  when 


WEEDS  OF   MEADOWS  AND   PASTURES  29 

well  grown,  send  out  rootstocks  in  all  directions.  From 
these  rootstocks  other  plants  arise,  so  that  a  continually 
expanding  thicket  of  shrubbery  is  soon  established.  The 
Smooth,  the  Dwarf  or  Mountain,  and  the  Staghorn  or  Vel- 
vet Sumachs,  are  the  common  nonpoisonous  species.  The 
Poison  Ivy  and  the  Poison  Sumach  or  Poison  Dogwood  are 
the  poisonous  species.  The  Poison  Ivy  is  one  of  the  most 
generally  distributed.  These,  however,  are  harmful  chiefly 
to  mankind  and  are  external  irritants  rather  than  internal 
poisons. 


A  LITTLE  BOOK 

OF 

PROFITLESS  WEEDS 

BY 

CHARLES  R.  JONES 


Tough  thistle  choked  the  fields  and  killed  the  corn, 
And  an  unthrifty  crop  of  weeds  was  borne. 

—  DRYDEN. 


ILLUSTRATED 

THE   BROWN   SCHOOL 
1910 


A  SUGGESTION  FOR  TITLE-PAGE  OF  BOOKLET  ON  WEEDS 


30  FARM   FRIENDS  AND   FARM   FOES 

OBSERVATIONS   FOR   PUPILS 
PASTURE  WEEDS 

1.  Make  a  list  of  twelve  weedy  plants  that  you  have  seen  growing  in 
the  pastures  of  your  locality. 

2.  Are  such  plants  more  troublesome  along  fences,  hedges,  or  walls, 
than  in  the  open  pasture  ? 

3.  Are  weeds  more  abundant  in  pastures  heavily  stocked  with  domes- 
tic animals  or  those  lightly  stocked  ? 

4.  What  are  the  best  ways  of  getting  rid  of  pasture  weeds  in  your 
vicinity  ? 

5.  If  a  weedy  pasture  is  near,  make  a  list  of  the  weeds  present  and 
mention  the  way  in  which  each  kind  probably  got  started  in  that  field. 

6.  How  often  are  pastures  plowed  up  and  reseeded  in  your  locality  ? 

MEADOW  WEEDS 

1.  Make  a  list  of  the  ten  most  troublesome  weeds  present  in  the 
meadows  of  your  locality. 

2.  See  if  you  can  tell  which  ones  were  probably  started  by  being 
mixed  with  grass,  grain,  or  clover  seed ;  which  were  blown  in  by  the 
wind ;  and  which  were  brought  in  in  other  ways. 

3.  Are  any  of  these  plants  that  have  been  recently  introduced  into 
your  region  ? 

4.  If  a  meadow  is  near,  make  a  list  of  the  weeds  present  and  mention 
the  way  in  which  each  kind  probably  got  started  in  that  field. 

5.  How  often  are  meadows  plowed  up  and  reseeded  in  your  locality  ? 

6.  Which   meadows  show  the  most   weeds,   those  recently  seeded 
down  or  those  that  have  been  seeded  down  for  a  long  time  ? 

READ  such  references  in  the  following  as  your  teacher  directs  ;  — 
Some  Poisonous  Plants  of  the  Northern  Stock  Ranges,  Farmers'  Bulletin  206. 
Thirty  Poisonous  Plants,  Farmers'  Bulletin   86.     Johnson-grass,  Farmers'  Bulletin 
279.    Canada  Thistle,  Circular  27,  Division  of  Botany,  U.  S.  Dept.  Agr. 


CHAPTER   III 


The  Weeds  of  Gardens  and  Cultivated  Fields 

THE  weeds  that  infest  gardens  and  cultivated  fields  are 
familiar  to  most  people.  Such  plants  are  seen  daily  by 
every  one  in  town  and  country,  and  must  be  constantly 
kept  in  mind  by  all  farmers  and  gardeners.  To  a  large 
extent  they  are  annuals  and  produce  seed  in  such  abundance 
that  neglected  soil  is  quickly  covered  with  young  plants. 
Most  of  them  are  easily  kept  in  check  when  the  ground  is 
given  proper  tillage. 

GRASS  FAMILY 

By  far  the  most  troublesome  of  these  garden  weeds  is 
the  Quack-grass  or  Witch-grass,  which  is  known  by  a  dozen 
other  names.  This  notorious  pest  multiplies  both  by  seeds 
and  by  underground  rootstocks 
that  penetrate  the  soil  in  all  direc- 
tions, sending  up  leafy  branches 
everywhere.  If  these  rootstocks 
are  cut  into  pieces,  each  piece 
will  produce  a  new  plant.  On 
this  account,  hoeing  and  culti- 
vating ground  infested  by  Witch- 
grass  is  likely  to  do  more  harm  than  good.  When  the 
grass  has  taken  complete  possession  of  a  piece  of  land,  it  is 
often  cut  for  hay,  but  this  only  leads  to  the  wider  scatter- 
ing of  the  seeds  through  the  fertilizers  from  the  barn. 

Quack-grass  thrives  upon  ordinary  tillage,  and  is  to  be 
subdued  only  by  a  vigorous  and  persistent  course  of  treat- 

31 


FARM  FRIENDS  AND  FARM  FOES 


ment.  It  is  often  said  that  to  kill  it,  you  must  dig  it  out, 
dry  it  on  a  rock,  burn  it,  and  then  be  very  careful  where 
you  put  the  ashes  !  In  gardens  and  limited  areas,  the  best 
way  is  to  dig  out  the  rootstocks,  when  no  crop  is  in  the 
ground,  with  a  tined  potato  digger  and  cart  them  away. 

By  keeping  persistently  at  the 
roots  every  spring  and  fall,  the 
land  can  finally  be  cleared.  Small 
patches  may  also  be  smothered  by 
covering  the  surface  with  boards, 
tarred  roofing  paper,  or  something 
similar. 

Several  species  of  annual  grasses 
are  likely  to  become  troublesome 
in  gardens  and  fields  during  the 
latter  part  of  the  growing  season. 
One  of  these  is  the  curious  Fly- 
away-grass or  Old-witch-grass,  the 
plume-like  seed  heads  of  which 
are  to  be  seen  every  autumn  roll- 
ing before  the  wind,  and  finally 
lodging  along  fences.  Because  of  these  heads  that  thus 
fly  along  the  surface  of  the  ground,  dropping  their  seeds 
as  they  go,  this  grass  is  likely  to  appear  even  in  ground 
that  has  been  kept  free  from  seeding  plants.  Consequently 
it  is  desirable  that  the  grass  be  kept  in  check  wherever 
it  appears. 

Two  species  of  Foxtail  or  Pigeon-grass  are  universal 
weeds.  The  Yellow  Foxtail  or  Common  Pigeon-grass 
seems  to  be  generally  more  abundant  than  the  Green  Fox- 
tail or  Bottle-grass.  They  are  very  similar,  except  for  the 
difference  in  color.  Both  appear  about  midsummer  in 
gardens,  cultivated  fields,  and  waste  places,  often  carpet- 


WEEDS   OF   GARDENS   AND   FIELDS  33 

ing  the  ground  with  their  spiked  heads.  When  mowed  off, 
they  send  up  new  heads,  which  are  able  to  develop  close  to 
the  soil  surface.  The  seeds  of  the  Foxtails  are  commonly 
distributed  in  clover  and  millet  seed,  and  so 
are  often  sown  with  these.  Persistent  late 
culture  and  hand  weeding  are  the  only  effi- 
cient means  of  checking  these  grasses. 

One  or  more  kinds  of  Crab-grass  or 
Finger-grass  are  very  likely  to  develop  after 
midsummer,  especially  in  wet  seasons  or  on 
moist  land.  These  have  the  peculiarity  of 
spreading  their  stems  in  all  directions,  the 
stems  striking  roots  into  the  soil  whenever 
in  close  contact  with  it.  This  makes  the 
plant  difficult  to  eradicate,  because  any  of 

SHEPHERDS  PURSE 

the  rooted  stems  left  will  continue  to  grow. 
Fortunately  it  is  an  annual  and  so  does  not  retain  posses- 
sion from  season  to  season.     It   is  likely  to  develop  in 
neglected  barnyards  and  thus  have  the  seeds  scattered  with 
the  fertilizers. 

The  seeds  of  the  Barnyard  Grass  are  also  very  likely  to 
be  scattered  in  the  way  just  mentioned.  This  is  a  tall  coarse 
plant,  often  reaching  a  height  of  three  or  four  feet.  It 
frequently  develops  in  corn  and  potato  fields  late  in  summer, 
getting  its  growth  after  cultivation  ceases.  It  is  compara- 
tively easy  to  subdue  by  hand  pulling.  Under  the  name 
Japanese  Millet  it  has  lately  been  added  to  the  list  of  de- 
sirable forage  plants. 

MUSTARD  FAMILY 

Several  abundant  garden  weeds  belong  to  the  Mustard 
family.  Wild  Mustard  or  Charlock,  Black  Mustard,  Wild 
Radish,  and  Peppergrass  are  familiar  illustrations.  These 


34       FARM  FRIENDS  AND  FARM  FOES 

are  all  found  in  gardens  more  or  less,  though  the  Mustards 
are  more  likely  to  be  troublesome  to  grain  and  forage 
crops. 

The  Shepherd's  Purse  is  one  of  the  garden  weeds  most 
likely  to  develop  early  in  the  season.  It  is  able  to  do  this 
because  it  is  a  winter  annual,  developing  the  autumn  be- 
fore into  a  rosette  of  low-lying  leaves.  In  spring  it  sends 
up  its  slender  central  stalk,  along  the  lower  and  middle 
parts  of  which  are  a  few  narrow  leaves,  some  having  curi- 
ously incised  margins,  while  along  the  upper  part  are  the 
small  white  flowers,  crowded  together  toward  the  top. 
These  develop  into  the  purse-shaped  seed  pods,  borne  on 
the  ends  of  slender  stems. 

This  familiar  plant  is  commonly  found  wherever  a  few 
inches  of  waste  ground  give  it  an  opportunity  to  grow. 
Tillage  late  in  autumn  or  early  in  spring  is  the  best  way  to 
destroy  it. 

PINK  FAMILY 

One  or  more  species  of  Chickweed  are  so  widely  distrib- 
uted that  they  occur  in  almost  every  garden.  The  Smooth 
Chickweed  is  known  by  its  smooth  leaves  and  stems,  and 
its  minute  white  flowers  with  the  green  pistils  longer  than 
the  petals.  It  is  a  winter  annual.  The  Mouse-ear  Chick- 
weed  is  known  by  its  hairy  leaves.  Technically  there  are 
two  species  known  by  the  latter  name ;  one  of  these  is  a 
perennial. 

These  Chickweeds  multiply  by  spreading  over  the  sur- 
face of  the  soil  as  well  as  by  seeds  which  are  produced  in 
abundance  throughout  the  season.  They  are  comparatively 
easy  to  keep  in  check  by  proper  tillage. 

During  the  latter  part  of  summer,  the  heart  of  the  care- 
less gardener  is  often  vexed  by  the  rapid  growth  of  the 


WEEDS   OF   GARDENS  AND   FIELDS  35 

succulent  Purslane  or  "pusley."  Its  thick  brown  stalks 
creep  along  the  ground,  spreading  rapidly  from  the  root, 
and  seriously  interfering  with  crop  growth.  The  leaves, 
as  well  as  the  stems,  are  smooth  and  thick,  while  the  pale 
yellow  flowers  borne  in  the  axils  of  the  leaves  generally  open 
only  in  the  morning,  when  the  sun  is  shining.  The  small 
seeds  are  produced  in  capsules,  the  tops  of  which  come  off 
when  the  seeds  ripen.  It  has  been  estimated  that  1,250,000 
seeds  are  sometimes  produced  by  a  single  plant.  Fortunately 
this  Purslane  is  an  annual,  requiring  only  frequent  surface 
tillage  for  its  prevention,  although  when  the  plants  become 
large,  it  is  necessary  to  remove  them  to  prevent  their  grow- 
ing again.  This  is  one  of  those  weeds  that  compel  the  gar- 
dener to  keep  a  soil  mulch  through  the  summer,  and  thus 
conserve  the  moisture  during  the  driest  season  of  the  year. 

GOOSEFOOT   AND    AMARANTH    FAMILIES 

The  plant  commonly  called  Lamb's  Quarters,  Goosefoot, 
or  White  Pigweed,  is  a  widespread  and  troublesome  gar- 
den pest.  Where  it  finds  room,  it  be- 
comes a  large  and  vigorous  weed,  five 
or  six  feet  high  and  about  two  feet  in 
diameter.  Usually  it  is  two  or  three 
feet  high.  The  leaves  are  somewhat 
arrow-shaped,  with  irregular  teeth  along 
the  margins,  and  rather  long,  slender 
petioles.  The  narrow  clusters  of  green- 
ish white  flowers  appear  in  the  axils 
of  the  leaves,  toward  the  ends  of  the 
branches.  The  general  color  of  the  plant  is  pale  green, 
with  a  whitish  powder  scattered  over  the  flowers  and  young 
growth,  and  often  over  the  leaves,  also.  The  small  seeds 
are  black  and  shiny  when  separated  from  their  greenish 


36  FARM   FRIENDS  AND   FARM  FOES 

covering.  They  are  developed  in  great  numbers,  and 
often  produce  plants  so  crowded  together  in  field  and  gar- 
den that  there  is  no  chance  for  the  regular  crop  to  mature. 

This  White  Pigweed  often  grows  rapidly,  and  should 
be  destroyed  by  surface  tillage.  If  it  gets  started  in  the 
garden,  frequent  cultivation  is  the  best  way  to  keep  it  in 
check. 

The  common  Pigweed  is  one  of  the  plants  most  char- 
acteristic of  neglected  gardens  in  the  latter  part  of 
summer.  The  broad,  wavy-margined  leaves  are  borne  on 
the  ends  of  long  petioles  that  arise  from  a  cylindrical  main 
stalk,  which  in  turn  grows  from  a  red  root.  The  plant  is 
sometimes  known  as  Redroot.  It  is  an  annual,  developing 
rather  late  in  the  season,  and  consequently  is  very  likely 
to  be  found  in  fields  of  corn  and  potatoes  after  cultivation 
ceases.  Each  plant  produces  great  numbers  of  small 
seeds,  some  of  which  may  ripen  as  early  as  August.  The 
pest  is  to  be  attacked  by  thorough  cultivation,  or  by  hand 
pulling  in  fields  where  late  tillage  is  impracticable. 

As  far  as  its  flowers  and  seeds  are  concerned,  the 
Tumbleweed  is  closely  related  to  the  Pigweed,  both  be- 
longing to  the  Amaranth  family  ;  but  in  its  manner  of 
growth  it  is  very  different.  The  Tumbleweed  sends  out 
numerous  branches,  that  give  it  a  broad  expanse,  so  that 
when  the  main  stalk  breaks  off  near  the  root,  it  is  able  to 
roll  and  tumble  along  the  ground  with  every  gust  of  wind, 
scattering  its  seeds  as  it  goes.  It  commonly  brings  up  be- 
side a  fence  or  other  obstruction,  where  regular  windrows 
of  the  plants  may  sometimes  be  seen.  It  is  easily  kept  in 
check  in  gardens  and  cultivated  fields  by  tillage  or  hand 
pulling. 


WEEDS  OF   GARDENS  AND   FIELDS  37 

SUNFLOWER  FAMILY 

The  Ragweed  or  Roman  Wormwood  is  a  pestiferous 
plant  found  in  most  situations  where  weeds  may  grow  late 
in  summer.  It  is  nearly  always  to  be  seen  along  paths 
and  highways,  in  fence  corners,  and  along  garden  borders, 
as  well  as  in  cornfields  and  wheat  stubble.  It  is  an  an- 
nual, and  has  a  straight  central  stalk  from 
which  many  spreading  branches  arise.  The 
latter  bear  numerous  leaves  with  deeply 
cut  lobes  and  many  small,  greenish,  incon- 
spicuous flowers.  As  in  the  case  of  the 
Horseweed,  to  which  the  Ragweed  is 
closely  related,  the  pollen-bearing  blossoms 
are  borne  along  the  sides  of  the  branches 
near  the  tips,  while  the  seed-bearing  flowers 
are  borne  along  the  lower  parts  of  the 
same  branches.  One  reason  the  Ragweed  is  so  ubiquitous 
is  because  the  young  plants  are  able  to  develop  in  hard 
soil  where  most  weeds  cannot  get  a  foothold. 

When  mowed  off  an  inch  or  two  above  the  ground,  the 
Ragweed  is  likely  to  produce  new  branches  from  the 
cut  main  stalk,  from  which  seeds  may  develop ;  conse- 
quently thorough  work  is  necessary  in  subduing  the  pest. 
One  effective  method  is  to  pasture  infested  fields  with 
sheep. 

In  the  Middle  West,  the  Giant  Ragweed  or  Horseweed 
is  one  of  the  most  abundant  plants.  Its  luxuriant  growth 
is  to  be  found  everywhere,  but  it  is  especially  vigorous  and 
troublesome  on  moist  bottom  lands.  Poorly  cultivated  or 
untilled  parts  of  such  fields  are  frequently  covered  with  a 
dense  growth  of  this  robust  annual,  the  seeds  of  which 
are  carried  by  water  from  one  valley  to  another.  It  often 


38  FARM   FRIENDS   AND   FARM   FOES 

reaches  a  height  of  ten  or  twelve  feet,  the  simple  stems 
shooting  straight  upward  and  bearing  along  their  ribbed 
sides  the  large  opposite  three-lobed  leaves  with  dentate 
margins.  The  flowers  are  small  and  inconspicuous,  being 
borne  in  rows  along  the  ends  of  the  branches.  The  staminate 
or  pollen-bearing  blossoms  are  above  the  pistillate  or  seed- 
bearing  flowers.  The  former  are  much  more  abundant 
than  the  latter.  Each  of  the  pistillate  flowers  bears  a 
single  seed.  As  the  Horseweed  is  an  annual,  it  may  be 
kept  in  check  by  thorough  cultivation,  or  in  untilled  lands 
by  repeated  mowings.  There  is  often  danger,  however, 
that  during  times  of  floods,  bottom  lands  may  be  reseeded 
from  regions  upstream. 

The  Clotbur  or  Cocklebur  is  another  pernicious  weed  of 
the  Sunflower  family,  which  commonly  develops  late  in  the 
season  in  gardens  and  cultivated  fields.  This  plant  is  eas- 
ily known  on  account  of  the  peculiar  burs,  or  seed  heads, 
covered  with  hooked  spines.  It  is  a  low-growing  annual, 
attaining  a  height  of  but  a  foot  or  two,  but 
spreading  over  quite  an  area.  The  prin- 
cipal stalks  are  tough  and  woody,  and 
bear  the  broad  triangular  leaves  on  the 
ends  of  long,  slender  petioles.  Two  sorts 
of  flowers  are  borne  by  each  plant,  stam- 
inate or  pollen-bearing,  which  appear  at 
the  upper  end  of  the  principal  stalk,  and 
pistillate  or  seed-bearing,  which  develop 
lower  upon  the  same  stalk.  The  pollen  drops  from  the 
former  upon  the  latter,  or  is  blown  from  plant  to  plant 
by  the  wind,  and  thus  fertilizes  the  embryo  seeds. 

The  bur  really  consists  of  a  lot  of  bracts  called,  when  thus 
grown  together,  the  involucre.  As  the  seeds  mature  the 
bur  hardens,  the  hooked  spines  becoming  stiffer  as  they 


WEEDS  OF   GARDENS  AND   FIELDS  39 

dry  out,  until  finally  they  are  strong  enough  to  cling  to  the 
hair  or  fur  of  any  passing  animal. 

Fortunately  the  Cocklebur  spreads  and  multiplies  only 
through  its  seeds,  so  that  it  is  comparatively  easy  to  keep 
in  check  in  cultivated  fields  by  means  of  clean  culture  con- 
tinued late  in  the  season. 

POTATO  FAMILY 

The  Horse  Nettle  is  a  perennial  weed  native  to  the 
southeastern  region  of  the  United  States,  whence  it  has 
gradually  spread  westward.  Its  general  resemblance  in 
leaf,  flower,  and  fruit  to  the  common  potato  shows  its  re- 
lation to  that  plant.  The  two  belong  to  the  same  genus 
—  Solanum.  The  rough,  prickly  plants  attain  a  height 
of  from  one  to  two  feet,  bearing  good-sized  oak-like  downy 
leaves,  with  long  spines  projecting  from  the  midrib  on 
both  the  upper  and  the  lower  surfaces.  The  flowers  are 
white  or  purple,  and  develop  into  round  yellow  berries. 
The  latter  are  composed  of  a  pulpy  substance  in  which 
many  small  seeds  are  embedded.  These  seeds  are  dis- 
tributed by  birds. 

Besides  the  seeds,  the  plant  spreads  and  reproduces  by 
slender  rootstocks  that  penetrate  the  soil  in  all  directions 
and  live  from  season  to  season.  These  make  the  Horse 
Nettle  a  difficult  pest  to  subdue.  Clean  cultivation  and  the 
eradication  or  starving  out  of  the  rootstocks  are  the  best 
methods. 

Like  the  Horse  Nettle,  the  Buffalo  Bur  is  a  native  of 
America,  having  originally  developed  upon  the  plains  of 
the  far  West,  where  its  burs  became  entangled  in  the  hairy 
fur  of  the  wandering  buffaloes.  Since  the  advent  of  the 
white  man,  the  plant  has  spread  eastward,  until  now  it  is 
found  in  many  regions  throughout  the  country.  Like  the 


40  FARM   FRIENDS  AND   FARM  FOES 

Horse  Nettle,  also,  this  plant  belongs  to  the  same  genus  as 
the  potato,  the  flowers  resembling  those  of  this  common 
vegetable  in  shape,  although  they  are  yellow  in  color.  It 
is  an  extremely  spiny  plant,  more  so  than  the  Horse  Nettle, 
and  its  fruit  develops  into  spinose  burs,  inside  which  are 
numerous  small  black  seeds.  These  become  attached  to 

clothing  or  the  hair  of  animals,  and 
are  thus  disseminated,  although  the 
whole  plant  is  sometimes  blown 
from  place  to  place,  carrying  the 
seeds  with  it. 

The  Buffalo  Bur  may  be  kept 
down,  if  seeding  is  prevented,  either 
by  mowing  or  cultivation. 

Nearly  a  score  of  species  of 
Ground  Cherries,  of  the  genus  Phys- 
alis,  are  found  in  North  America. 
All  are  readily  recognized  by  the 
curious  berry-like  fruit  inclosed  in 
the  inflated  bell-shaped  calyx  that 
forms  a  pod-like  covering.  The 
foliage  resembles  that  of  the  to- 
mato. One  of  the  most  abundant 
sorts  is  called  the  Husk  Tomato,  or  Strawberry  Tomato, 
and  is  grown  as  an  edible  fruit. 

These  Ground  Cherries  are  readily  kept  in  check  in  a 
well-tilled  garden.  Most  of  them  are  annuals,  though  at 
least  one  is  a  perennial. 


GROUND  CHERRY  OR 
PHYSALIS 


WEEDS  OF  OTHER  FAMILIES 

Many  years  ago,  perhaps   in  the  days  of   Pocahontas, 
a  weedy    plant    appeared   in   the  gardens  of  Jamestown, 


WEEDS   OF   GARDENS   AND   FIELDS  41 

Virginia.  It  was  a  very  distinctive  species  with  good- 
sized,  dark  green  leaves,  large  white  flowers,  and  curiously 
spined  fruit  capsules.  It  had  a  decidedly  disagreeable 
odor,  and  was  found  to  be  very 
poisonous.  So  the  plant  became 
well  known,  and  when  it  spread 
to  the  gardens  of  the  surrounding 
region,  it  was  called  Jamestown 
Weed,  a  name  that  was  gradually 
contracted  to  Jimson  Weed,  by 
which  it  is  now  generally  known. 

It  is  also  called  Thorn  Apple,  Jamestown  Lily,  Apple  of 
Peru,  and  Mad-apple.  Possibly  the  last  name  is  due  to 
the  fact  that  infusions  of  leaves  have  been  used  for  the 
cure  of  hydrophobia.  Or  it  may  be  due  to  the  fact  that 
the  plant  when  eaten  produces  convulsions  and  delirium. 

In  addition  to  the  white-flowering  Jimson  weed,  there  is 
a  very  similar  purple-flowering  species.  Both  are  annuals 
from  the  tropics,  and  are  especially  abundant  in  the  South- 
ern states.  Nearly  every  year  children  are  poisoned  by 
eating  the  seeds.  These  plants  should  be  destroyed  wher- 
ever they  are  seen. 

There  are  several  creeping  plants  that  are  troublesome 
as  weeds.  One  of  the  worst  of  these  is  called  the  Hedge 
Bindweed  or  Wild  Morning  Glory.  Its  rootstock  is  peren- 
nial, while  the  stem  and  leaves  die  down  every  autumn. 
Its  leaves  are  somewhat  arrow-shaped,  and  its  white  or 
purplish  flowers  bear  a  general  resemblance  to  those  of  the 
cultivated  Morning  Glory.  It  is  especially  troublesome  on 
low  moist  land. 

The  Wild  Morning  Glory  is  propagated  both  by  seeds 
and  by  the  spreading  of  underground  roots.  On  account 
of  these  roots  it  is  a  difficult  weed  to  eradicate.  Hoeing 


42       FARM  FRIENDS  AND  FARM  FOES 

and  pulling  are  effective  when  only  a  few  of  the  plants 
are  present. 

A  similar  species  is  Wild  Buckwheat  or  Black  Bindweed. 
The  stems  and  blossoms  of  this  plant  are  smaller  than  are 
those  of  the  Bindweed,  while  the  flowers,  instead  of  being 
produced  singly  on  stems,  are  quite  small  and  clustered  to- 
gether in  racemes.  It  is  called  Wild  Buckwheat  because  its 
seeds  are  quite  similar  to  those  of  buckwheat.  It  is  an  an- 
nual species,  and  consequently  is  not  very  difficult  to  subdue 
by  cultivation. 

A  number  of  the  more  abundant  weeds  are  likely  to  de- 
velop in  gardens  and  plowed  fields,  during  the  latter  part 
of  summer.  In  some  cases  they  are  really  a  benefit,  in 
that  they  enforce  surface  tillage  during  the  season  when  a 
soil  mulch  is  most  needed.  In  fields  of  corn,  potatoes,  and 
some  other  crops,  however,  such  late  tillage  is  impracti- 
cable, and  about  the  only  way  to  fight  the  weeds  is  to  pull 
them  up  by  hand. 

OBSERVATIONS   FOR   PUPILS 

1.  How  many  of  the  weeds  treated  of  in  this  chapter  infest  gardens 
and  cultivated  fields  in  your  locality  ?     Here  is  the  list :  — 

Barnyard  Grass  Hedge  Bindweed 

Black  Bindweed  Horse  Nettle 

Buffalo  Bur  Jimson  Weed 

Chickweed  Lamb's- quarters 

Crab-grass  Pigweed 

Finger-grass  Purslane 

Fly-away-grass  Quack-grass 

Giant  Ragweed  Ragweed 

Green  Foxtail  Shepherd's  Purse 

Ground  Cherry  Tumbleweed 
Yellow  Foxtail 

2.  What  other  weeds  occur  in  gardens  and  cultivated  fields  in  your 
locality  ? 


WEEDS  OF  GARDENS  AND   FIELDS  43 

3.  Make  a  list  of  the  field  and  garden  weeds  you  are  acquainted  with, 
and  print  the  names  in  alphabetical  order  on  a  page  of  your  booklet. 

4.  Make  a  careful  study  of  such  of  these  weeds  as  your  teacher  thinks 
desirable,  incorporating  the  results  into  your  booklet.     The  following 
outlines  may  prove  helpful  for  such  studies  :  — 


PURSLANE 

i.  Covnt  the  number  of  seeds  in  one  "pusley"  capsule. 

?..  Count  the  number  of  capsules  on  one  long  branch. 

3.  Estimate  the  number  of  seeds  produced  by  the  plant. 

4.  Count  the  number  of  plants  in  a  space  two  feet  square,  and  estimate 

the  number  of  seeds  produced  in  a  square  rod. 

5.  How  are  "pusley"  seeds  distributed  ? 

6.  When  do  you  find  Purslane  most  abundant  ? 

7.  Make  a  drawing  of  stem,  leaf,  and  fruit. 


LAMB'S  QUARTERS  OR  WHITE  PIGWEED 

1.  Why  should  this  be  called  White  Pigweed  ? 

2.  Where  have  you  found  it  most  abundant  ? 

3.  How  are  the  seeds  scattered  ? 

4.  Do  you  know  how  it  looks  when  young  ? 

5.  Have  you  seen  any  leaves  affected  by  leaf  miners  ?     If  so,  rear  some 

of  the  adult  flies  from  them,  and  see  whether  they  resemble  the  flies 
you  can  easily  rear  from  spinach. 

6.  How  early  should  the  plants  be  destroyed  to  prevent  their  maturing 

seed? 
'/.    Draw  a  good-sized  leaf,  showing  petiole,  veins,  and  margin. 

OUTLINE  FOR  OTHER  WEEDS 

1 .  What  sort  of  root  has  this  plant  ? 

2.  Does  it  spread  by  underground  rootstocks  ? 

3.  How  is  it  protected  from  being  eaten  by  animals  ? 

4.  When  do  the  flowers  appear  ?     Describe  them. 

5.  When  do  the  seeds  ripen  ?     How  are  they  scattered  ? 

6.  Estimate  the  number  of  seeds  on  one  plant. 

7.  What  do  the  young  seedlings  look  like  ?     When  may  they  be  found  ? 


44 


FARM   FRIENDS   AND   FARM   FOES 


8.  In  what   condition  does  the  plant  pass  the  winter  —  in  the  seed 

state,  or  as  a  living  plant,  or  both  ? 

9.  How  is  it  commonly  introduced  to  new  fields  ? 

10.  In  what  ways  may  it  be  destroyed  or  prevented  from  growing  ? 

1 1 .  Make  some  or  all  of  these  drawings  :  — 


Root 
Leaf 


Flower 
Seed 


GlLL-OVER-THE-GROUND 


CHAPTER   IV 
The  Weeds  of  Grain  and  Forage  Crops 

THE  weeds  that  infest  fields  of  grain  and  forage  crops 
are  commonly  introduced  with  the  seed.  In  many  cases, 
however,  the  weed  roots  or  seeds  may  be  present  in  the 
soil  because  of  neglect  of  crops  previously  grown  upon  the 
land,  or  the  seeds  may  be  scattered  through  the  fields  during 
autumn,  winter,  and  spring  before  the  grain  or  forage  crop 
is  sown.  Consequently  the  surest  way  to  prevent  injury  in 
such  fields  is  to  sow  clean  seed  and  adopt  good  agricultural 
methods. 

GRASS  FAMILY 

Perhaps  the  most  notorious  grain-field  plant  is  Chess  or 
Cheat  Grass.  In  earlier  days  there  was  much  discussion 
in  regard  to  the  origin  of  this  pernicious  plant.  The  idea 
was  very  commonly  upheld  that  wheat  turned  to  Chess,  so 
that  under  certain  conditions,  as  it  was  supposed,  a  farmer 
might  sow  good  wheat  seed  and  reap  only  a  crop  of  Chess. 
It  seems  likely  that  this  was  the  basis  for  the  use  of  the 
common  name  Cheat.  It  has  long  been  known,  however, 
that  Chess  comes  from  seed  of  its  own,  and  not  from  wheat, 
so  that  when  the  Chess  appears  it  is  certain,  either  that  its 
seed  was  present  in  the  ground  before  sowing  or  that  it 
was  mixed  in  with  fertilizers  or  the  wheat  that  was  used 
for  seeding.  It  is  well  established  that  the  seed  of  Chess 
may  lie  dormant  in  the  soil  for  several  seasons,  and  this 

45 


46 


FARM   FRIENDS   AND    FARM   FOES 


probably  is  the  explanation  of  its  presence  in  many  grain 
fields,  in  which  no  Chess  seed  developed  the  previous 
season. 

Chess  is  a  winter  annual,  and  its  slender  seeds  .are  some- 
what similar  to  oats,  although  they  are  darker  in  color,  and 
the  grain  is  of  smaller  size.  These  seeds  are  likely  to  be 
found  in  cheap  qualities  of  clover,  oats,  and  wheat  seed, 


Mixture  of  weed  seeds  commonly  found  in  low-grade  alsike  clover  seed :  a,  alsike 
clover;  b,  white  clover;  c,  red  clover;  d,  yellow  trefoil;  e,  Canada  thistle; 
/  dock ;  g,  sorrel ;  h,  buckhorn  ;  i,  rat-tail  plantain ;  /£,  lamb's-quarters  ;  /,  shep- 
herd's purse;  m,  mayweed;  n,  scentless  camomile  ;  o,  white  campion  \  p,  night- 
flowering  catch-fly;  q,  oxeye  daisy;  r,  small-fruited  false  flax;  s,  cinquefoil; 
f,  two  kinds  of  peppergrass ;  u,  catnip;  v,  timothy;  x,  chickweed;  y,  Canada 
bluegrass ;  z,  clover  dodder ;  /,  mouse-ear  chickweed ;  2,  knot-grass ;  j,  tum- 
bling amaranth  ;  4,  rough  amaranth ;  j,  heal-all ;  6,  lady's  thumb.  (Enlarged.) 

although,  as  in  the  case  of  many  other  pernicious  plants, 
the  public  inspection  of  seeds  is  driving  these  poorer  qual- 
ities out  of  the  market.  When  a  field  is  infested  with 
Chess,  it  may  well  be  planted  to  a  hoed  crop  for  two  or 
three  seasons.  This  procedure,  and  the  sowing  of  pure 
seed,  will  prove  an  adequate  preventive. 


WEEDS   OF   GRAIN  AND   FORAGE   CROPS          47 

In  the  great  spring  wheat  regions  of  the  Northwest,  the 
Wild  Oat  is  one  of  the  most  troublesome  weeds  in  fields  of 
oats.  This  plant  bears  a  striking  resemblance  to  the  or- 
dinary cultivated  oats,  from  which  it  is  easily  known  by  the 
long-tipped  awns  borne  by  the  terminal  florets  of  each 
cluster  of  flowers,  and  by  the  fact  that  the  kernel  or  grain 
is  very  light.  When  present  in  an  oats  field,  these  Wild 
Oats  mature  earlier  than  the  main  crop  and  in  an  irregular 
fashion,  many  of  the  individual  florets  dropping  away  as 
they  ripen.  The  presence  of  the  plant  not  only  reduces 
the  regular  crop,  but  also  sometimes  causes  trouble  because 
the  stiff  awns  irritate  the  mouth  parts  of  the  animals  to 
which  the  crop  is  fed. 

The  seeds  of  Wild  Oats  retain  their  vitality  for  a  long 
period  when  buried  deeply  in  the  soil.  Consequently,  a 
badly  infested  field  may  require  several  seasons'  tillage  in 
other  crops  before  all  the  seeds  present  have  germinated. 
A  carefully  planned  rotation  is  the  best  method  of  getting 
rid  of  the  plant. 

MUSTARD  FAMILY 

In  many  localities,  the  most  vexatious  weeds  in  grain 
fields  are  those  belonging  to  the  Mustard  family.  The 
seeds  of  these  are  very  commonly  mixed  with  oats  and  other 
grains,  so  they  are  sown  at  seeding  time.  One  of  the  most 
generally  troublesome  is  the  Charlock,  Wild  Mustard,  or 
English  Mustard,  as  it  is  sometimes  called.  This  was  origi- 
nally a  native  of  Europe,  but  is  now  very  generally  dis- 
tributed in  America.  It  is  especially  troublesome  in  fields 
of  oats,  the  young  mustard  plants  growing  along  with  the 
oats  and  materially  lessening  the  crop.  Charlock  is  dis- 
tinguished from  the  other  Mustards  by  a  pod,  long  and 
knotted,  and  having  at  the  tip  a  rather  thick,  two-edged  beak. 


48       FARM  FRIENDS  AND  FARM  FOES 

The  Black  Mustard  is  a  much  more  prickly  plant,  having 
pods  that  are  more  or  less  oblong,  smooth,  and  four-angled. 
A  single  plant  of  either  of  these  Mustards  may  produce 
from  10,000  to  1 5,000  seeds.  This  accounts  for  the  enormous 
numbers  of  them  that  often  appear  in  neglected  fields. 

In  many  parts  of  Canada  and  the  United  States,  the 
Tumbling  Mustard  or  Tall  Mustard  has  recently  become 
a  troublesome  pest.  This  species  seems  to  have  been  in- 
troduced with  the  soil  carried  as  ballast  by  ships,  and  dumped 
on  the  so-called  ballast  grounds  at  Philadelphia.  It  has 
since  been  widely  distributed  by  railroads,  and  is  able  to 
develop  under  a  great  variety  of  climatic  conditions.  Like 
the  other  Mustards,  this  is  an  annual.  It  branches  freely, 
and  reaches  a  height  of  from  two  to  four  feet.  The  small 
yellowish  flowers  are  borne  along  the  tips  of  the  slender 
branches,  and  are  less  conspicuous  than  those  of  the  Char- 
lock. The  seed  pods  are  very  slender,  and  are  commonly 
two  or  three  inches  long.  This  species  is  closely  related  to 
the  more  widely  distributed  Hedge  Mustard,  the  pod  of 
which  is  much  shorter  and  of  larger  diameter. 

In  the  case  of  all  these  Mustards,  as  with  most  annual 
weeds,  careful  cultivation  with  a  hoed  crop  for  a  series  of 
years  is  necessary  for  complete  extermination  in  a  field.  The 
seeds  of  many  of  the  plants  of  the  Mustard  family  retain 
their  vitality  for  several  years,  so  that  those  which  are 
buried  deep  in  plowing,  are  likely  to  be  brought  to  the 
surface  long  after  they  matured,  and  find  favorable  condi- 
tions for  growth.  It  is  especially  important  that  grain 
used  for  sowing  be  free  from  the  seeds  of  any  of  these 
plants. 

Numerous  experiments  have  shown  that  young  mustard 
plants  may  be  killed  in  grain  fields  without  serious  injury 
to  the  grain  crop  by  spraying  with  a  solution  of  one  part 


WEEDS   OF   GRAIN  AND   FORAGE    CROPS  49 

iron  sulphate  to  four  parts  water  by  weight.  The  applica- 
tion should  be  made  on  a  fair  day  after  the  dew  has  evapo- 
rated. 

Another  member  of  the  Mustard  family,  which  is 
troublesome  in  fields  of  winter  grain,  as  well  as  in  those  of 
flax,  is  the  so-called  False  Flax.  This  is  a  pest  from 
Europe  which  has  been  introduced  into  America  compara- 
tively recently.  Its  resemblance  to  Flax  is  indicated  by  its 
common  name.  The  flowers  and  seeds,  however,  are  much 
smaller  than  those  of  Flax.  In  appearance  and  habit  of 
growth,  it  also  bears  a  general  resemblance  to  Shepherd's 
Purse  and  Peppergrass.  Like  these  weeds,  it  may  be 
either  an  annual  or  a  winter  annual;  that  is,  the  seeds  may 
germinate  in  spring  and  blossom  the  same  season,  or  they 
may  germinate  in  autumn,  the  plants  living  through  the 
winter  and  blossoming  the  next  season.  As  a  rule,  it  is 
only  the  latter  that  mature  their  seeds,  the  season  in  the 
Northern  states  being  too  short  for  the  seeds  of  those 
plants  that  germinate  in  spring  to  reach  maturity. 

False  Flax  is  generally  introduced  as  a  mixture  in  flax 
seed,  clover  seed,  and  various  grass  seeds  ;  consequently  all 
such  seeds  should  be  carefully  examined  before  being  sown. 
When  the  pest  has  become  established,  rotation  with  a  hoed 
crop  is  necessary  to  exterminate  it. 

WEEDS  OF  OTHER  FAMILIES 

The  Cockle  or  Corn  Cockle  is  a  well-known  pest  in  grain 
fields.  Its  presence  is  generally  due  to  impure  seed,  the 
black  seeds  of  the  Cockle  being  sown  with  the  wheat  or 
other  grain.  It  is  an  annual,  so  that  it  causes  little  trouble 
unless  sown  with  the  seed.  It  grows  to  a  height  of  three 
or  four  feet,  and  has  a  slender  stem  with  very  few  branches, 
each  of  which  bears  on  its  tip  a  good-sized  reddish-purple 


50  FARM   FRIENDS   AND    FARM   FOES 

blossom.  There  are  comparatively  few  of  the  long,  narrow 
leaves,  which,  with  the  stem  and  outer  part  of  the  flowers, 
are  covered  with  a  coat  of  fine  hairs. 

The  dark  purple  or  blackish  seeds  are  produced  in  an  ob- 
long pod.  They  are  threshed  with  the  wheat ;  and  as  they 
are  nearly  the  size  and  weight  of  the  wheat  kernel,  it  is 
very  difficult  to  separate  the  Corn  Cockle  seeds  from  the 
grain.  In  consequence  the  flour  is  of  inferior  quality.  The 
presence  of  the  seeds  is  shown  by  the  black  particles  of  the 
pulverized  seed  coat.  Flour  badly  contaminated  by  Cockle 
seeds  is  injurious  when  eaten,  as  they  contain  a  poisonous 
principle  that  produces  disease  and  death. 

The  Cockle  plants  are  easily  pulled  up  in  wheat  fields 
and  should  be  removed,  especially  from  all  fields  that  are 
intended  to  produce  seed  grain. 

Few  weedy  plants  have  such  distinctive  beauty  as  has 
the  famous  Field  Poppy  or  Corn  Poppy  of  the  English 
poets.  In  England  the  fields  of  wheat  are  called  corn 
fields,  although  in  America  this  term  is  usually  restricted 
to  Indian  Corn.  The  Field  Poppy  has  long  been  a  pest  in 
European  wheat  fields;  but  it  gives  to  the  landscape  a 
glow  of  scarlet  color,  much  as  our  own  meadows  are 
decorated  with  the  Oxeye  Daisy.  This  Field  Poppy  has 
been  introduced  into  many  regions  in  America,  probably 
through  adulterated  seed,  and  threatens  to  become  trouble- 
some wherever  it  appears.  It  is  so  conspicuous  a  plant 
that  it  can  scarcely  be  overlooked,  and  when  first  introduced 
into  a  locality  it  should  be  exterminated.  This  is  also  one  of 
the  garden  Poppies  and  of  course  there  is  danger  that  it 
may  spread  to  cultivated  fields. 

The  famous  Russian  Thistle  or  Russian  Tumbleweed  is 
another  European  plant  that  has  become  destructive  in 
America.  The  history  of  the  introduction  of  this  pest  has 


WEEDS  OF   GRAIN  AND   FORAGE   CROPS          51 

been  carefully  traced.  Apparently  it  was  first  brought  in 
by  immigrants  from  Russia  in  the  great  Northwest,  about 
1873,  and  since  then  it  has  spread  with  marvelous  rapidity, 
not  only  by  being  blown  across  long  stretches  of  prairie, 
but  also  by  means  of  railroad  trains,  and  probably  in 
other  ways.  It  has  attracted  more  attention  than  any 
other  weedy  plant  of  recent  introduction,  and  has  been 
the  cause  of  a  great  awakening  in  regard  to  the  whole 
subject. 

The  Russian  Tumbleweed  is  an  annual  that  starts  as  a 
slender  seedling  bearing  a  general  resemblance  to  a  very 
young  pine  tree.  Its  leaves  are  slender,  soft,  and  velvety. 
It  grows  rapidly,  however,  and  toward  midsummer  takes 
on  a  spiny  appearance,  spreading  out  to  cover  an  area  three 
or  four  feet  in  diameter,  with  the  height  nearly  as  great, 
and  a  rounded  outline  similar  to  that  of  our  common 
Tumbleweeds.  When  the  seeds  are  finally  mature  and 
ready  to  be  dispersed,  the  main  stalk  breaks  off  at  the 
surface  of  the  ground  and  the  plant  rolls  away.  It  then 
justifies  its  German  name  "Wind  Witch,"  or  its  Russian 
name  "  Leap  the  Fields."  With  the  impetus  given 
by  a  violent  wind,  the  plants  go  rolling  and  tumbling 
across  the  prairies,  to  be  caught  in  great  windrows  when  an 
obstacle  interferes.  As  they  roll  along  they  drop  their 
seeds  by  the  way,  so  that  the  country  traversed  is  likely  to 
become  thoroughly  infested. 

While  the  greater  part  of  the  weeds  that  infest  grain 
fields  arise  from  seeds  present  or  introduced,  it  sometimes 
happens  that  when  meadow  or  pasture  land  is  broken  up 
and  planted  to  grain,  there  is  trouble  from  perennial  weeds 
whose  roots  or  rootstocks  remain  in  the  soil.  Thus,  if  a 
meadow  is  infested  with  milkweeds  and  is  planted  to  oats, 
the  milkweeds  will  multiply  rapidly  under  the  favorable 


52  FARM   FRIENDS   AND   FARM   FOES 

conditions  for  their  growth.     In  such  cases  rotation  with  a 
hoed  crop  is  desirable. 

THE  PARASITIC  DODDER 

All  the  weeds  so  far  discussed  in  this  chapter  injure  the 
crop  by  robbing  the  soil  of  food  and  moisture,  or  by  oc- 
cupying the  space  above  the  soil  to  the  exclusion  of  the 
cultivated  plants.  There  is  one  group  of  pernicious  weeds, 
however,  which  do  more  than  this,  for  they  actually  attack 
the  green  tissues  of  the  crop  and  rob  them  of  the  life- 
giving  sap.  These  plants  are  commonly  called  Dodders, 
and  there  are  several  species  that  attack  different  crops. 
In  their  life  history,  however,  they  are  very  similar  to  one 
another. 

The  young  Dodder  plant  starts  from  a  seed  well  stocked 
with  nourishment.  When  the  seed  germinates,  this  nour- 
ishment enables  it  to  develop  into  a  seedling  which  soon 
comes  in  contact  with  the  stalk  of  some  green  plant. 
Then  the  little  Dodder  sends  out  from  along  the  sides  of 
its  own  stalk  curious  rootlike  projections  that  penetrate  the 
tissues  of  the  other  plant  and  draw  out  the  sap.  There  is 
thus  established  the  relation  of  parasite  and  host :  the 
parasite  is  the  Dodder  sucking  the  life  sap  from  its  victim, 
which  is  the  host  plant.  The  root  and  lower  stem  of 
the  Dodder  soon  wither.  In  the  case  of  clover,  which  is 
often  infested  by  Dodder,  the  clover  plant  continues  to 
grow,  having  roots  in  the  ground  and  leaves  in  the  air, 
but  those  clover  stalks  which  are  attacked  by  the  Dodder 
become  dwarfed  as  well  as  hard  and  woody. 

As  the  Dodder  grows,  it  constantly  twines  around  more 
stalks  of  its  host  plant,  sending  into  their  tissues  more  of 
the  rootlike  suckers,  and  after  a  time  developing  small 
blossoms  which  later  mature  into  seed.  As  the  Dodder  is 


WEEDS   OF    GRAIN  AND   FORAGE   CROPS          53 

a  parasite,  it  has  none  of  the  green  coloring  matter  of 
most  plants,  for  it  is  not  able  to  manufacture  starch  and 
other  organic  material  from  the  inorganic  substances  in 
earth  and  air.  Instead  of  this,  it  utilizes  for  its  growth  the 
materials  thus  organized  by  the  green  leaves  of  its  host. 
The  Dodders  are  commonly  yellow  or  orange  in  color. 
They  have  no  leaves. 

The  seeds  of  Dodder  are  a  common  impurity  in  many 
grain,  grass,  and  forage  seeds.  Such  seeds  should,  of 
course,  be  carefully  inspected  before  planting,  and  if  seri- 
ously infected  should  not  be  used.  When  a  field  is  al- 
ready infested,  the  Dodder  may  be  destroyed  by  mowing 
and  removing  the  crop  before  the  Dodder  blossoms,  or 
later  the  crop  may  be  mowed  and  the  ground  burned  over 
after  the  crop  thus  cut  has  dried  sufficiently  to  burn.  In 
Western  alfalfa  fields  Dodder  is  often  troublesome  the 
first  year  after  seeding,  though  less  so  in  later  years. 

PREVENTIVE  MEASURES 

Any  study  of  the  weeds  that  infest  grain  and  forage 
crops  makes  it  obvious  that  the  most  important  methods 
of  preventing  injury  by  such  pests  are :  first,  the  sowing 
of  clean  seed,  that  is,  grain  free  from  the  seeds  of  weedy 
plants  ;  second,  the  use  of  fertilizers  free  from  weed  seeds ; 
and  third,  a  proper  rotation  with  other  crops.  To  insure 
pure  seed,  constant  inspection  by  state  and  government 
officials  of  all  seeds  offered  for  sale  is  necessary.  To  in- 
sure fertilizers  free  from  weed  seeds,  care  in  feeding  do- 
mestic animals  is  necessary.  To  insure  proper  rotation  of 
crops,  the  adoption  of  improved  agricultural  methods  in 
every  community  is  necessary.  With  these  conditions 
right  there  need  be  little  trouble  from  weedy  plants  in  any 
locality.  There  is  always  danger,  however,  that  some  new 


54  FARM  FRIENDS  AND   FARM  FOES 

pest  will  be  introduced,  and  it  is  very  desirable  that  the 
people  of  each  community  should  be  on  the  alert  for  such 
newly  introduced  weeds.  In  order  that  they  may  do  this, 
each  school  should  have  a  collection  of  weeds  and  their 
seeds  for  reference,  and  a  study  should  be  made  of  the 
weedy  plants  of  the  locality.  Any  unknown  plants  may 
be  sent  to  the  State  Experiment  Station,  or  to  the  Depart- 
ment of  Agriculture  at  Washington  for  determination. 

OBSERVATIONS   FOR   PUPILS 

1 .  What  weeds  have  you  observed  in  connection  with  such  of  the 
following  crops  as  are  largely  grown  in  your  locality :  — 

Alfalfa 

Alsike  Clover 

Oats 

Red  Clover 

Wheat 

2.  Is  there  any  evidence  to  show  that  part  of  these  were  introduced 
with  seed  ? 

3.  Examine  with  a  lens  samples  of  forage  plant  seeds  for  sale  in  your 
locality.     Compare  the  seeds  with  the  pictures  in  Farmers'  Bulletin  382. 

4.  Determine  the  percentage  of  adulteration  of  the  crop  seed  with 
other  seeds. 

5.  If  you  are  unable  to  determine  what  seeds  are  present  as  adul- 
terants, send  samples  to  your  State  Experiment  Station  or  to  the  Seed 
Laboratory,  Department  of  Agriculture,  Washington,  D.C. 

READ  such  references  in  these  publications  as  your  teacher  directs  :  — 

Dodder  in  Relation  to  Farm  Seeds,  Farmers'  Bulletin  306.    The  Adulteration 
of  Forage-plant  Seeds,  Farmers'  Bulletin  382. 


CHAPTER  V 
The  Economics  of  Weeds 

EVERY  farmer  realizes  that  weeds  are  among  the  most 
important  factors  in  success  or  failure  in  agriculture. 
They  occur  wherever  the  soil  is  cultivated  and  stand  ever 
ready  to  take  the  place  of  the  crop  planted  if  proper  tillage 
is  not  given.  They  not  only  rob  the  crop  of  sunshine  and 
needed  space  in  earth  and  air,  but  they 
also  deprive  the  soil  of  more  or  less  of  its 
available  plant  food,  draw  out  its  mois- 
ture, and  according  to  the  present  belief 
of  some  authorities  actually  poison  the 
soil  for  other  plants. 

Weeds,  however,  are  by  no  means  to 
be  considered  an  unmixed  evil.  In  many 
cases  they  are  rather  to  be  thought  of  as 
a  blessing  in  disguise,  for  they  compel 
that  tillage  of  the  land  which  is  neces- 
sary for  the  conservation  of  moisture  and 
the  healthy  growth  of  most  crops.  "  The 

truth  is,"  writes  L.  H.  Bailey  in  a  famous 

,  MEADOWSWEET 

paragraph,    "that   weeds    always    have 

been  and  still  are  the  closest  friends  and  helpmates  of  the 
farmer.  It  was  they  which  first  taught  the  lesson  of  the 
tillage  of  the  soil,  and  it  is  they  which  never  allow  the  les- 
son, now  that  it  has  been  partly  learned,  to  be  forgotten. 
The  one  only  and  sovereign  remedy  for  them  is  the  very 

55 


56  FARM  FRIENDS  AND   FARM  FOES 

tillage  which  they  have  introduced.  When  their  mission  is 
finally  matured,  therefore,  they  will  disappear,  because 
there  will  be  no  place  in  which  they  can  grow.  It  would 
be  a  great  calamity  if  they  were  now  to  disappear  from 
the  earth,  for  the  greater  number  of  farmers  still  need  the 
discipline  which  they  enforce.  Probably  not  one  farmer  in 
ten  would  till  his  lands  well  if  it  were  not  for  these  pains- 
taking schoolmasters,  and  many  of  them  would  not  till  at 
all.  Until  farmers  till  for  tillage's  sake,  and  not  to  kill  the 
weeds,  it  is  necessary  that  the  weeds  shall  exist,  but  when 
farmers  do  till  for  tillage's  sake,  then  weeds  will  disappear 
with  no  effort  of  ours." 

While  the  beneficence  of  weeds  as  a  whole  must  be  ad- 
mitted as  a  fortunate  fact,  it  is  also  true  that  often  they 
are  not  even  a  blessing  in  disguise.  Like  other  things 
in  Nature,  the  laws  that  govern  them  involve  many  in- 
conveniences in  special  cases.  Rain  is  a  blessing, 
but  sometimes  it  causes  suffering  and  loss  of  prop- 
erty and  even  of  life.  Winds  are  necessary,  but 
often  do  serious  harm  by  their  violence.  With 
weeds,  as  with  these  direct  forces  of  Nature,  man 
must  adapt  his  operations  to  suit  the  conditions 
that  he  finds  upon  his  land  in  his  efforts  to  make 
it  productive. 

Examples  of  weeds  that  could  easily  be  dis- 
pensed with  are  readily  pointed  out.  The  Mus- 
tard in  a  newly  planted  grain  field  does  not  indi- 
cate that  tillage  is  needed,  although  it  does  in- 
dicate that  there  has  been  carelessness  in  seed 
selection.  During  rainy  seasons  the  hoe  and  cultivator 
must  frequently  be  kept  in  operation  to  subdue  weeds 
much  oftener  than  any  requirements  of  the  crop  alone 
would  necessitate.  The  weeds  that  appear  late  in  the 


SPUD 


ECONOMICS  OF  WEEDS  57 

season  in  corn  and  potato  fields  require  hand  pulling 
because  tillage  then  would  injure  the  crops,  and  often 
even  hand  pulling  involves  some  loss  through  the  disturb- 
ance cf  the  roots. 

The  most  famous  definition  of  a  weed  is  that  it  is  a  plant 
out  of  place.  In  soil  devoted  to  a  crop  of  a  given  kind, 
the  presence  even  of  other  crop  plants  is  generally  not 
wanted.  So  under  some  circumstances  our  ordinary  grains, 
vegetables,  and  flowers  may  appear  as  weeds.  In  fact,  in 
the  case  of  the  flowers  many  weeds  have  originated  as  gar- 
den escapes,  and  there  is  always  danger  that  new  ones  may 
be  so  introduced. 

THE  STRUGGLE  FOR  LIFE 

It  is  well  known  that  the  most  troublesome  weeds  are 
those  best  equipped  in  the  struggle  for  life.  By  being 
able  to  grow  quickly  where  other  plants  grow  slowly,  by 
producing  many  seeds  where  other  plants  produce  few 
seeds,  or  by  being  able  to  do  anything  else  that  enables  it 
to  get  on  in  the  world  better  than*  its  neighbors  a  plant 
has  an  advantage  that  tends  to  make  it  a  weed.  There  is 
always  an  intense  struggle  for  soil,  moisture,  air,  and  sun- 
light, and  the  plants  best  fitted  to  take  advantage  of  con- 
ditions existing  at  a  given  time  and  place  will  win.  It  is 
the  farmer's  business  so  to  plan  his  operations  that  the 
crops  he  sows  will  have  the  advantage  of  all  weedy  in- 
truders. 

One  of  the  chief  advantages  that  most  weeds  have  in 
the  struggle  for  life  lies  in  the  production  of  great  num- 
bers of  seeds.  This  is  well  shown  in  the  following  esti- 
mates by  the  Kansas  Experiment  Station  of  the  number  of 
seeds  ripened  by  one  plant,  made  after  careful  studies  of 
each  species :  — 


60       FARM  FRIENDS  AND  FARM  FOES 

season,  it  is  likely  to  be  less  dangerous  than  if  it  lives 
two  or  more  seasons.  Like  other  plants,  weeds  are  com- 
monly grouped  as  annuals,  living  but  one  year,  biennials, 
living  two  years,  and  perennials,  living  many  years.  The 
phrase  winter  annuals  is  given  to  those  plants  that  start 
their  growth  in  autumn  and  finish  their  development  the 
following  spring  or  summer. 

The  remedial  measures  to  be  taken  against  weeds  depend 
largely  upon  the  term  of  life.  The  annuals  live  from  year 
to  year  by  means  of  their  seeds.  Consequently  the  preven- 
tion of  seeding  by  tillage  or  other  means  and  the  destruction 
of  the  seed  are  the  most  important  general  measures.  It 
has  lately  been  found  that  some  annuals  like  the  mustards 
may  safely  be  killed  in  grain  fields  by  spraying  with  a  weak 
solution  of  iron  sulphate.  The  biennials  reproduce  also 
by  seeds,  and  are  to  be  treated  much  as  the  annuals.  The 
perennials  commonly  reproduce  both  by  seeds  and  by  root- 
stocks  or  other  vegetative  growths,  so  that  their  destruction 
is  generally  more  difficult  than  in  the  case  of  the  annuals 
and  biennials. 

The  methods  that  may  be  employed  for  the  destruction 
of  the  roots  or  rootstocks  of  perennial  weeds  have  been 
well  summarized  by  L.  H.  Dewey  in  these  words  :  — 

(1 )  They  may  be  dug  up  and  removed,  a  remedy  that  can 
be  practically  applied  only  in  small  areas. 

(2)  They  may  be  killed  by  applying  chemicals  either  to 
the  freshly  cut  root  or  at  the  base  of  the  main  stem.     Salt, 
strong  brine,  coal  oil,  crude  sulphuric  acid,  and  carbolic 
acid  have  been  successfully  used  for  this  purpose.     A  few 
drops  of  carbolic  acid  applied  at  the  base  of  the  main  stem 
with  an  ordinary  machine-oil  can  is  the  best  method  that 
has  been  yet  devised  for  killing  weeds  with  chemicals  (ex- 
cept spraying  with  sulphate  of  iron). 


ECONOMICS  OF  WEEDS 


61 


(3)  Rootstocks  or  perennial  roots   may  be   starved  to 
death  by  preventing  any  development  of  green  leaves  or 
other  parts  above  ground.     This  may  be  effected  by  build- 
ing straw  stacks  over  small  patches,  by  persistent,  thorough 
cultivation  in  fields,  by  the  use  of  the  hoe  or  spud  in  waste 
places,  and  by  salting  the  plants  and  turning  sheep  on  in 
permanent  pastures. 

(4)  The  plants  may  usually  be 
smothered  by  dense  sod-forming 
grasses  or  by  a  crop  like  clover  or 
millet  that  will  exclude  the  light. 

(5)  Most  rootstocks  are  readily 
destroyed  by  exposing   them  to 
the  direct  action  of  the  sun  dur- 
ing the  summer  drought,  or  to  the 
direct  action  of  the  frost  in  the 
winter.     In  this  way  plowing,  for 
example,  becomes  effective. 

(6)  Any  cultivation  that  merely 
breaks    up    the    rootstocks    and 

leaves  them  in  the  ground,  especially  during  wet  weather, 
only  multiplies  the  plant  and  is  worse  than  useless,  unless 
the  cultivation  is  continued  so  as  to  prevent  the  growth 
above  ground.  Plowing  and  fitting  corn  ground  in  April 
and  May,  and  cultivating  at  intervals  until  the  last  of  June, 
then  leaving  the  land  uncultivated  during  the  remainder  of 
the  season,  is  one  of  the  best  methods  that  could  be  pur- 
sued to  encourage  the  growth  of  couch-grass  and  many 
other  perennial  weeds. 

Recent  studies  by  Spillman  and  Gates  have  shown  that 
the  rootstock  grasses,  like  quack  grass,  Bermuda  grass,  and 
Johnson  grass,  are  readily  killed  out  by  allowing  the  fields 
to  become  meadows  and  pastures,  so  that  a  dense  sod  will 


GOLDEN  ROD  SEEDHEADS 


60  FARM  FRIENDS  AND   FAR1 

season,  it  is  likely  to  be  less  dangerus  than  if  it  lives 
two  or  more  seasons.  Like  other  plats,  weeds  are  com- 
monly grouped  as  annual sy  living  but  ne  year,  biennials, 
living  two  years,  and  perennials^  livinpnany  years.  The 
phrase  winter  annuals  is  given  to  thce  plants  that  start 
their  growth  in  autumn  and  finish  thir  development  the 
following  spring  or  summer. 

The  remedial  measures  to  be  taken  aainst  weeds  depend 
largely  upon  the  term  of  life.  The  anuals  live  from  year 
to  year  by  means  of  their  seeds.  Consquently  the  preven- 
tion of  seeding  by  tillage  or  other  mean  and  the  destruction 
of  the  seed  are  the  most  important  geeral  measures.  It 
has  lately  been  found  that  some  annua,  like  the  mustards 
may  safely  be  killed  in  grain  fields  by  sraying  with  a  weak 
solution  of  iron  sulphate.  The  biennds  reproduce  also 
by  seeds,  and  are  to  be  treated  much  a  the  annuals.  The 
perennials  commonly  reproduce  both  b  seeds  and  by  root- 
stocks  or  other  vegetative  growths,  so  tat  their  destruction 
is  generally  more  difficult  than  in  the  ase  of  the  annuals 
and  biennials. 

The  methods  that  may  be  employee  for  the  destruction 
of  the  roots  or  rootstocks  of  perennii  weeds  have  been 
well  summarized  by  L.  H.  Dewey  in  thse  words:  — 

(1)  They  may  be  dug  up  and  remove,  a  remedy  that  can 
be  practically  applied  only  in  small  ares. 

(2)  They  may  be  killed  by  apply  in  Chemicals  either  to 
the  freshly  cut  root  or  at  the  base  of  th  main  stem.     Salt, 
strong  brine,  coal  oil,  crude  sulphuric  acid,  and  carbolic 
acid  have  been  successfully  used  for  th;  purpose.     A  few 
drops  of  carbolic  acid  applied  at  the  bae  of  the  main  stem 
with  an  ordinary  machine-oil  can  is  te  best  method  that 
has  been  yet  devised  for  killing  weeds  vith  chemicals  (ex- 
cept spraying  with  sulphate  of  iron). 


EONOMICS  OF  WEEDS 


61 


(3)  Rootstocks  )r  perennial  roots   may  be   starved  to 
death  by  preventig  any  development  of  green  leaves  or 
other  parts  above  round.     This  may  be  effected  by  build- 
ing straw  stacks  oer  small  patches,  by  persistent,  thorough 
cultivation  in  field  by  the  use  of  the  hoe  or  spud  in  waste 
places,  and  by  saing  the  plants  and  turning  sheep  on  in 
permanent  past;; 

(4)  The  plants  nay  usually  be 
smothered  by  dene  sod-forming 
grasses  or  by  a  cro  like  clover  or 
millet  that  will  exlude  the  light. 

(5)  Most  rootstcks  are  readily 
destroyed  by  expsing   them  to 
the  direct  action  c  the  sun  dur- 
ing the  summer  drught,  or  to  the 
direct  action  of  te  frost  in  the 
winter.     In  this  \iy  plowing,  for 
example,  becomeseffective. 

(6)  Any  cultiv:.  on  that  merely 
breaks    up    the    Dotstocks    and 

leaves  them  in  th  ground,  especially  during  wet  weather, 
only  multiplies  th  plant  and  is  worse  than  useless,  unless 
the  cultivation  is  ontinued  so  as  to  prevent  the  growth 
above  ground.  lowing  and  fitting  corn  ground  in  April 
and  May,  and  cult/ating  at  intervals  until  the  last  of  June, 
then  leaving  the  lad  uncultivated  during  the  remainder  of 
the  season,  is  oneof  the  best  methods  that  could  be  pur- 
sued to  encourag  the  growth  of  couch-grass  and  many 
other  perennial  v?eds. 

Recent  studies  y  Spillman  and  Gates  have  shown  that 
the  rootstock  grases,  like  quack  grass,  Bermuda  grass,  and 
Johnson  grass,  anreadily  killed  out  by  allowing  the  fields 
to  become  meado\s  and  pastures,  so  that  a  dense  sod  will 


GOLDEN  ROD  SEEDHEADS 


62 


FARM  FRIENDS  AND   FARM  FOES 


form.  Then  cut  or  feed  off  the  grass  frequently  to  induce 
a  shallow  development  of  rootstocks.  These  may  then  be 
turned  up  by  shallow  plowing  and  destroyed  by  clean  cul- 
ture, summer  fallowing,  or  winter  freezing. 

LESSONS  FROM  WEEDS 

The  most  important  general  lessons  we  may  learn  from 
our  study  of  weeds  are,  first,  that  good  agriculture  is  the  best 
preventive  of  their  injuries,  and,  second,  that  this  must  be 
practiced  not  only  by  all  the  farmers  of  a  given  community, 
but  by  all  farmers  everywhere.  So  it  becomes  the  duty 
of  each  one  to  adopt  the  best  methods  practicable  on  his 
own  farm  as  well  as  to  encourage  in  every  way  possible 
the  practice  of  such  methods  in  every  locality. 


HARDHACK 


OBSERVATIONS   FOR   PUPILS 

Choose  certain  weeds  which  you  have  not  before 
reported  upon  and  see  if  you  can  answer  these  ques- 
tions about  each  :  — 

1.  Where  did  it  come  from  ? 

2.  How  does  it  spread  ? 

3.  How  long  does  it  live  ? 

4.  How  does  it  pass  the  winter  ? 

5.  How  does  it  injure  the  crop  ? 

6.  Is  it  poisonous  or  hurtful  to  domestic  animals  ? 

7.  In  what  ways  may  it  be  destroyed  ? 

When  you  have  a  composition  to  write,  choose 
some  weed  for  a  topic  and  use  these  questions  as  an 
outline  for  your  guidance. 


PART    II 

FRIENDS   AND    FOES    AMONG   THE 
INSECTS 


COVER  DESIGN  FOR  A  BOOKLET  ON  INSECTS 


THE  BOOKLETS  ON  INSECTS 

At  least  two  insect  booklets  may  be  prepared  by  each  pupil,  one  on  In- 
sect Enemies  and  another  on  Insect  Friends.  The  drawings  and  reports 
upon  the  Observations  for  Pupils  suggested  at  the  ends  of  the  chapters  will 
furnish  abundant  material  for  voluminous  booklets. 

In  making  drawings  of  insects  so  as  to  show  a  back  view  with  each  side 
symmetrical,  a  butterfly  with  wings  spread,  for  example,  it  is  best  to  draw 
one  half  beside  a  straight  line,  then  to  transfer  this  half  by  means  of  tracing 
paper  to  the  other  side  of  the  line.  It  is  easier  thus  to  get  both  sides  alike. 


CHAPTER  VI 
Orthoptera:  the  Grasshoppers,  Crickets,  and  Cockroaches 

THE  Grasshoppers,  Crickets,  Cockroaches,  Walking 
Sticks,  and  a  few  other  species  make  up  the  order  of  straight- 
winged  insects  called  Orthoptera.  Practically  all  of  them 
are  injurious,  or  capable  of  becoming  so.  With  the  excep- 
tion of  the  Tree  Crickets  and  the  Mantids  few  of  them  are 
likely  to  be  of  great  service  to  man,  except  possibly  as  a 
source  of  food  to  poultry. 

The  insects  of  this  order  are  characterized  by  having 
biting  mouth  parts,  incomplete  transformations,  and  four 
wings  —  the  front  pair  usually  being  thickened,  while  the 
hind  pair  are  membranous  and  folded  like  a  fan  beneath 
the  front  ones.  This  is  a  comparatively  small  group,  but 
one  in  which  there  are  some  very  destructive  species.  In 
America  the  Rocky  Mountain  Locust  has  done  enormous 
damage.  In  the  Old  World  the  locust  plagues  of  both  an- 
cient and  modern  times  were  due  to  insects  belonging  to 
this  order. 

STRUCTURE  OF  A  GRASSHOPPER 

If  you  examine  a  grasshopper  carefully,  one  of  the  first 
things  you  notice  is  that  the  body  is  divided  into  three  im- 
portant sections.  At  the  front  end  is  the  head ;  next  to 
this  are  two  closely  connected  parts  that  bear  the  legs 
and  wings  and  together  form  the  thorax  ;  next  to  the  thorax 
js  a  part  divided  into  rings  —  the  abdomen. 

65 


66 


FARM  FRIENDS  AND  FARM  FOES 


a  bed  e 

MOUTH  PARTS  OF  GRASSHOPPER 

a,  labrum ;    b,  mandible ;    c,  tongue ;    d,  maxilla ;  e,  la- 
bium.     Magnified. 


The  head  varies  greatly  in  shape  with  different  species 
of  grasshoppers,  but  in  general  it  is  larger  above  than  be- 
low. From  near  the  middle  of  the  front  there  project  two 
slender  feelers  or  antenna,  each  of  which  is  composed  of 

a  number  of  dis- 
tinct rings  or 
segments  joined 
together.  Just 
above  the  base 
of  each  antenna 
is  a  large  com- 
pound eye,  the  surface  of  which  through  a  lens  resembles 
the  surface  of  a  honeycomb.  Each  eye  has  a  great  number 
of  hexagonal  divisions  :  these  are  the  facets  which  make 
up  the  compound  eye.  There  are  three  simple  eyes  on  the 
grasshopper's  head — two  between  the  compound  eyes  and 
one  in  the  middle  line  above.  These  are  very  different  in 
structure  from  the  compound  eyes,  being  merely  small, 
round,  lenslike  objects.  These  simple  eyes  are  often 
called  ocelli. 

Below  are  the  mouth  parts  of  the  grasshopper.  Begin- 
ning from  above,  we  see  first  a  large  four-sided  flap  or  lip, 
which  moves  up 
and  down  on  a 
basal  hinge  ;  this 
is  the  upper  lip 
or  labrum.  Be- 


Nymph 


GRASSHOPPER 


Adult 


neath  it  there  is  a  pair  of  rather  large  jaws  or  mandibles 
attached  so  as  to  move  sideways,  and  having  sharp,  toothed, 
cutting  edges.  On  the  inside  of  the  mouth  between  the 
mandibles  is  the  tongue ;  and  below  this  are  the  second 
jaws  or  maxillce,  while  still  lower  is  the  underlip  or  labium, 
with  its  labial  palps  or  feelers. 


GRASSHOPPERS  AND   CRICKETS  67 

Directly  back  of  the  head,  there  is  a  large  capelike  seg- 
ment bearing  a  pair  of  legs.  This  is  the  first  division  of 
the  thorax,  and  is  called  the  prothorax.  The  remainder 
of  the  thorax  is  made  up  of  two  parts  united.  The  one  in 
the  middle  is  the  mesothorax ;  this  bears  the  front  wings 
and  the  middle 
legs.  Behind  this 
is  the  metathorax  ; 
this  bears  the  hind 
wings  and  the  hind 
legs. 

The  front  wings 

a  OBLONG  LEAF-WINGED  GRASSHOPPER 

are  long  and  slen- 
der, and  when  at  rest  serve  as  a  protective  covering  to  the 
hind  wings.  The  latter  are  then  folded  in  "longitudinal 
plaits  like  a  fan.  When  the  grasshopper  is  flying,  the  front 
wings  are  extended  at  right  angles  to  the  body,  and  the 
hind  wings  are  stretched  out. 

The  abdomen  is  composed  of  a  number  of  joints  or  seg- 
ments, which  move  freely  upon  one  another  at  their  points 
of  contact.  In  female  specimens  the  abdomen  ends  in 
four-pointed  projections  by  mean's  of  which  the  hole  in  the 
ground  for  the  eggs  is  made ;  these  form  the  ovipositor  or 
^gg-depositor. 

SHORT-HORNED  LOCUSTS 

The  common  Grasshoppers  or  short-horned  Locusts  form 
one  of  the  most  important  families  (Acridiidae).  These 
have  short  antennae  or  "  feelers,"  short  ovipositors,  and  but 
three  joints  to  the  tarsi —  the  short  joints  at  the  ends  of 
the  legs.  They  feed  upon  grasses  and  other  forage  crops, 
and  are  often  very  destructive.  In  many  of  the  males, 
there  is  a  sound-producing  apparatus. 


68 


FARM  FRIENDS  AND  FARM  FOES 


COMMON  CRICKET 
Female 


The  Red-legged  Locust  is  one  of  the  commonest 
members  of  this  family.  Its  eggs  are  laid  in  the  ground 
early  in  autumn  and  remain  there 
through  the  winter.  The  next  sum- 
mer they  hatch  into  small  grasshopper^ 
that  resemble  the  adult  in  general  ap- 
pearance, but  of  course  are  much 
smaller  and  have  no  wings.  They 
molt  or  cast  their  skins  several  times 
during  the  next  six  weeks,  and  then 
they  become  full  grown  with  well- 
developed  wings. 

The  famous  Rocky  Mountain  Locust 
is  very  similar  to  the  Red-legged  spe- 
cies. Fortunately  it  is  unable  to  de- 
velop continuously  except  at  high  al- 
titudes, such  as  |  the  plateaus  of  the 
Rocky  Mountains.  Here  it  used  to  become  so  abundant 
that  it  was  forced  to  migrate 
for  food.  At  such  times,  enor- 
mous numbers  of  the  grass- 
hoppers flew  toward  the  Mis- 
sissippi Valley,  where  they 
fed  upon  all  kinds  of  grasses 
and  grains  and  many  other 
plants.  As  they  came  sud- 
denly in  enormous  swarms,  it 
was  impossible  to  fight  them 
successfully,  and  they  often 
did  great  damage. 

There  are  many  other  spe- 
cies of  grasshoppers  belong- 
ing to  this  family,  which  are  common  and  widely  distrib- 


TREE  CRICKETS 
Male  above ;   female  below 


GRASSHOPPERS  AND    CRICKETS  69 

uted.  The  Carolina  Locust  is  one  of  the  most  familiar. 
It  is  abundant  along  roadsides  and  may  be  known  by  its 
hind  wings  with  yellow  borders.  The  Bird  Grasshopper 
is  our  largest  species. 

MEADOW  GRASSHOPPERS 

The  more  slender  Meadow  Grasshoppers  or  Long-horned 
locusts  form  another  distinct  family  (Locustidae).  These 
have  long,  slender  antennae  or  "  feelers,"  conspicuous, 
sword-shaped  ovipositors,  and  four  joints  to  the  tarsi. 
Nearly  all  the  members  of  this  family  are  green  in 
color.  They  live  chiefly  on  grasses  and  other  herbaceous 
plants,  though  some  species  are  common  in  trees  and 
shrubs.  The  Meadow  Grasshoppers,  the  Katydids,  and 
the  wingless  cricket-like  Grasshoppers  are  the  important 
members  of  this  family. 

CRICKET  FAMILY 

The  family  to  which  the  Crickets  belong  is  called  the 
Gryllidae.  These  insects  are  characterized  by  having  hind 
legs  adapted  to  jumping,  long,  slender  antennae,  and  hori- 
zontal wings  with  the  outside  edge  turned  down  at  a  right 
angle  to  the  main  part.  In  most  Crickets  there  are  pecul- 
iar projections  called  stylets  at  the  hind  end  of  the  body, 
and  there  is  usually  in  the  females  a  spear-shaped  ovipos- 
itor. 

The  principal  types  of  Crickets  are  Tree  Crickets,  Black 
Crickets,  and  Mole  Crickets.  The  first  live  on  trees  and 
shrubs  above  ground,  the  second  on  the  ground,  and  the 
third  in  holes  in  the  ground.  In  the  case  of  the  Black 
Crickets,  eggs  are  deposited  in  the  soil  early  in  autumn 
and  remain  unhatched  until  the  following  season.  Some 
specimens,  however,  are  generally  to  be  found  in  winter  in 


yo  FARM  FRIENDS  AND   FARM  FOES 

a  half-grown  condition,  so  that  these  insects  may  hibernate 

in  two  stages  of  their  life. 

The  Tree  Crickets   are   generally   greenish  or  whitish 

insects,  living  on  the  leaves  and  branches  of  trees,  shrubs, 
and  herbs.  They  feed  upon  plant  lice  or 
aphides,  and  thus  differ  in  their  food 
habits  from  most  of  the  order.  But  they 
often  do  considerable  damage  to  rasp- 
berry canes  by  depositing  their  eggs  in 
long  rows  in  the  pith.  Such  canes  are 
likely  to  split  open  and  winter-kill. 

The  Mole  Crickets  are  among  the  most 
remarkable  examples  of  insect  life.  They 
are  perfectly  adapted  to  an  underground, 
burrowing  life.  The  front  legs  are  de- 
veloped into  digging  organs  by  means 
of  which  the  insect  can  make  a  tunnel 
in  the  soil,  through  which  the  cylindri- 
cal body  easily  passes.  They  are  brown 
in  color,  and  their  food  consists  of  under- 
MOLE  CRICKET  ground  roots  of  various  sorts. 

COCKROACHES  AND  WALKING  STICKS 

The  Cockroaches  (Blattidae)  are  characterized  by  their 
flattened  forms,  their  legs  fitted  for  running,  their  flat  over- 
lapping front  wings,  and  their  long,  bristlelike,  many-jointed 
antennae.  Many  forms  of  Cockroaches  are  wingless,  though 
the  typical  full-grown  form  has  well-developed  wings. 
These  insects  feed  upon  almost  anything,  being  commonly 
found  about  kitchens  and  sheds,  especially  where  there  are 
water  pipes.  Some  species  are  also  found  in  the  woods, 
under  the  bark  of  trees,  where  they  feed  upon  a  variety  of 
materials.  Probably  the  original  home  of  all  the  species 


GRASSHOPPERS  AND    CRICKETS  71 

was  in  the  forest.  The  eggs  are  deposited  in  curious  little 
brown  packets,  that  may  often  be  found  under  the  loose 
bark  of  fallen  logs. 

The  only  other  important  members  of  the  order  Orthop- 
tera  are  the  Walking  Sticks,  which  occasionally  are  injurious, 
and  the  Mantids,  which  are  generally  useful  in  that  they 
feed  upon  various  sorts  of  destructive  insects. 

OBSERVATIONS   FOR   PUPILS 
SHORT-HORNED  GRASSHOPPERS  OR  TRUE  LOCUSTS 


1 .  Get  a  few  good-sized  grasshoppers  —  the  larger  the  better.     Kill 
them  in  a  cyanide  bottle  or  by  immersing  in  alcohol.     Study  the  struc- 
ture carefully  to  see  if  you  can  make  out  all  the  details  mentioned  on 
pages  65-67  of  this  chapter. 

2.  Collect  a  lot  of  grasshoppers  in  a  meadow  or  pasture.     How  do 
the  young  differ  from  the  adults  ?     Rear  a  few  in  a  vivarium,  feeding 
with  clover  or  grass. 

3.  Place  a  piece  of  sod  in  the  bottom  of  a  box  or  a  wide  glasr  cylin- 
der.    Put  a  few  full-grown  grasshoppers  in  also.     See  if  you  get  eggs 
laid. 

4.    Look  up  some  of  these  references  :  — 

The  Insect  Book,  pages  332-335.     American  Insects,  pages  136-147.     Nature  Bi- 
ographies, pages  89-95.     Life  Histories  of  American  Insects,  pages  67-81. 


1.  Write  or  tell  a  story  with  this  title  :  The  Life  of  a  Grasshopper. 
Describe :  — 

Where  and  when  the  eggs  are  laid. 

What  the  eggs  look  like. 

When  the  eggs  hatch. 

What  the  young  grasshoppers  look  like. 

The  growth  of  the  young  grasshoppers. 

Their  food. 

When  they  become  full  grown. 

2.  Illustrate  your  story  with  sketches  :  if  written,  draw  on  paper;  if 
told,  draw  on  the  blackboard. 


72  FARM   FRIENDS   AND   FARM   FOES 


LONG-HORNED  OR  MEADOW  GRASSHOPPERS 

1 .  Get  a  few  Meadow  Grasshoppers  of  different  kinds  and  put  in  a 
vivarium.     Feed  with  clovers  or  grasses. 

2.  In  what  ways  do  these  differ  from  the  true  locusts  or  common 
grasshoppers  ? 

3.  Watch  to  see  if  you  can  find  out  just  how  they  sing. 

4.  Look  up  some  of  these  references  :  — 

The  Insect  Book,  pages  336-340.     American  Insects,  pages  149-156.    Stories  of 
Insect  Life,  Second  Series,  pages  6-10. 

CRICKETS 

1.  Collect  some  Black  Crickets  and  keep  in  a  glass  vivarium  with  sod 
in  the  bottom.     Observe  whether  you  can  see  them  move  their  wings  as 
they  sing.     See  if  you  can  get  some  to  lay  their  eggs. 

2.  You  can  generally  get  Tree  Crickets  in  summer  and  autumn  by 
beating  branches  of  trees  and  shrubs  over  an  open  inverted  umbrella. 
Keep  some  in  a  vivarium,  providing  aphides  for  them  to  feed  upon. 

3.  Look  up  some  of  these  references  :  — 

The  Insect  Book,  pages  341-344.     American  Insects,  pages  157-161.     Life  His- 
tories of  American  Insects,  pages  45-58. 

WALKING  STICKS 

1.  You  can  often  get  live  Walking  Sticks  by  beating  branches  over 
an  umbrella.     Keep   in   a  vivarium   and   insert  leafy  twigs  for  food. 
Notice  how  quiet  the  insects  remain  by  day. 

2.  Look  up  these  references  :  — 

The  Insect  Book,  pages  323-325.    Nature  Biographies,  pages  58-63. 


CHAPTER  VII 


Hemiptera :  The  True  Bugs 

WHILE  the  word  bug  has  been  in  common  English  use 
for  a  long  time  as  applying  to  an  insect  of  almost  any  kind, 
the  entomologists  restrict  the  word  to  a  certain  group  of 
insects  which  they  call  Hemiptera  or  Half-winged  Insects. 
The  mouth  parts  of  the  members  of  this  order  are  formed 
for  sucking,  and  the  transformations  are  incomplete,  their 
life  changes  resembling  those  of  the  grasshoppers  rather 
than  those  of  the  butterflies  and  moths.  An  immense 


this 


group, 


number  of  noxious  insects  are  included  in 
some  of  the  most  notorious  being  the  Squash 
Bug,  Chinch  Bug,  the  various  kinds  of  aph- 
ides or  plant  lice  and  of  the  scale  insects  or 
bark  lice,  the  Periodical  Cicada,  and  many 
other  equally  injurious  pests. 

The  life  history  of  these  insects  is  well  il- 
lustrated by  that  of  the  common  Black  Squash 
Bug.  This  pest  appears  in  the  garden  in 
early  summer,  and  the  females  soon  deposit 
their  eggs  upon  the  young  squash  plants. 
These  eggs  are  small,  rounded  objects,  more 
or  less  triangular  in  their  general  outline.  In 
from  six  to  fifteen  days  they  hatch  into  tiny- 
bugs,  which  grow  into  the  form  and  size  of  the  parents. 

The  newly  hatched  Squash  Bug  is  more  brilliantly  colored 
than  at  any  later  time  in  its  life,  and  these  colors  make  it 
very  conspicuous  against  the  green  background  of  the 

73 


SQUASH  BUG 
Magnified 


74       FARM  FRIENDS  AND  FARM  FOES 

leaves.  The  abdomen  and  the  hind  part  of  the  thorax  are 
light  green ;  the  legs  and  feelers  or  antennae  are  a  beauti- 
ful crimson ;  the  head  and  front  part  of  the  thorax  are  a 
light  crimson ;  while  the  margins  of  the  eyes  are  darker. 
This  brilliancy,  however,  lasts  for  a  short  time  only.  An 
hour  after  hatching,  the  crimson  is  noticeably  darker,  and 
in  a  few  hours  the  insect  is  nearly  black. 

The  young  Squash  Bugs  soon  begin  their  attacks  upon 
the  plant  by  inserting  their  tiny  beaks  into  the  succulent 
tissues  of  the  leaves.  In  their  general  habits  they  resem- 
ble the  adults.  After  about  three  days  of  this  feeding,  the 
abdomen  becomes  noticeably  swollen  and  the  color  some- 
what lighter.  This  is  an  indication  that  the  period  of 
molting  has  arrived.  These  young  bugs  are  often  called 
larvce  or  nymphs.  They  now  assume  a  quiet,  stationary 
attitude.  The  process  of  molting  begins  by  the  splitting 
of  the  skin  lengthwise  along  the  middle  of  the  back,  the 
split  extending  along  the  thorax  and  the  front  of  the  abdo- 
men. The  time  required  to  complete  this  molting  opera- 
tion varies  greatly,  but  generally  is  not  longer  than  an  hour 
or  two. 

A  few  hours  after  the  first  molt,  when  the  bugs  have 
taken  on  their  normal  color,  they  are  considerably  lighter 
than  before.  They  are  also  more  alert.  They  feed  again 
upon  the  sap  of  the  leaves  for  about  nine  days,  when  they 
undergo  their  second  molt.  After  this  has  taken  place,  so 
that  the  nymph  is  in  its  third  larval  stage,  the  body  is 
larger  and  flatter,  with  the  margins  more  sharply  denned 
and  the  color  somewhat  darker  than  in  the  second  stage. 

The  most  notable  difference  shown  by  the  insect  in  the 
fourth  stage,  which  is  entered  upon  by  the  third  molt  about 
eight  days  after  the  second,  is  the  noticeable  development 
of  the  wing  pads.  These  become  more  conspicuous  than 


HEMIPTERA:   THE  TRUE  BUGS  75 

before.  After  living  in  this  fourth  stage  for  about  a  week, 
the  insect  molts  for  the  fourth  time,  entering  upon  its  fifth 
stage.  It  is  now  quite  different  in  appearance,  and  is 
easily  recognized  as  a  full-grown  nymph,  —  a  condition 
analogous  to  the  pupa  state  of  butterflies  and  moths,  in  that 
it  is  the  stage  immediately  preceding  the  adult.  The 
wing  pads  are  greatly  enlarged,  while  the  thorax  is  wid- 
ened and  lengthened.  The  body  is  more  rectangular  and 
so  similar  to  a  mature  bug  that  at  a  little  distance  it  may 
readily  be  mistaken  for  the  latter. 

The  full-grown  nymph  lives  in  this  fifth  stage  about 
nine  days  before  the  final  molt,  by  which  it  matures  into 
the  adult  Squash  Bug. 

THE  CHINCH  BUG 

The  Chinch  Bug  has  a  life  history  similar  to  that  of  the 
Squash  Bug,  but  it  does  much  more  damage  because  it  at- 
tacks the  great  grain  crops  —  corn,  wheat,  oats,  and  simi- 
lar staples.  The  areas  in  which  it  occurs  in  greatest 
abundance  are  shown  by  the  dots  on  the  map  below.  It 
has  been  estimated  that  during  the  sixty  years  from  1850  to 
1910  the  losses  due  to  this  insect  exceeded  $300,000,000. 

The  full-grown  Chinch  Bugs  pass  the  win- 
ter in  the  shelter  of  thick  grass,  fallen  leaves, 
or  other  protection,  and  come  forth  in  the 
spring.     They   then  scatter  to  such   grain 
crops  as  they  can  find.     Here  they  lay  their 
eggs,  one  bug  often  laying  four  or  five  hun- 
dred eggs.     The  young  bugs  soon  hatch  and       CHINCH  BuG 
attack  the  grain  plants  by  sucking  the  sap 
through  their  pointed  beaks.     When  they  are  abundant, 
they  actually  hide  much  of   the  surface   of   the   leaf   or 
stalk,  and  of  course  kill  the  plants. 


76       FARM  FRIENDS  AND  FARM  FOES 

The  young  Chinch  Bugs  pass  through  a  series  of  molts 
very  similar  to  those  of  the  Squash  Bugs.  Those  that 
hatch  from  eggs  laid  in  spring  become  full  grown  about 
midsummer  or  a  little  later.  They  then  lay  eggs  for  an- 
other brood.  These  become  full-grown  before  winter  and 
hibernate  in  such  protection  as  they  can  find. 

The  destruction  of  Chinch  Bugs  in  their  winter  quarters 
is  one  of  the  most  effective  remedial  measures.  By  burn- 


AREAS  OVER  WHICH  THE  CHINCH  BUG  OCCURS  IN  MOST  DESTRUCTIVE 

NUMBERS 

ing  over  strips  of  grass  lands  along  fences  late  in  the  fall 
or  early  in  the  spring,  many  bugs  may  be  destroyed.  They 
may  also  be  attracted  to  strips  or  patches  of  trap  crops, 
such  as  millet,  wheat,  or  corn,  where  they  may  be  plowed 
under  or  otherwise  killed.  They  are  often  trapped  in  fur- 
rows and  killed  by  spraying  with  kerosene. 

Under  certain  weather  conditions  these  bugs  may  be 
killed  in  vast  numbers  by  the  Chinch  Bug  Fungus  —  a 
parasitic  disease  that  spreads  rapidly  in  moist  air.  This 


HEMIPTERA:   THE  TRUE   BUGS  77 

disease  has  been  propagated  artificially  and   distributed 
over  wide  areas  by  state  officials  to  good  advantage. 

HARLEQUIN  CABBAGE  BUG 

Throughout  the  Southern  states,  the  Harlequin  Cab- 
bage Bug  is  one  of  the  best-known  insects.  It  is  called 
by  many  common  names,  due  to  its  abundance  and  its  con- 
spicuous markings  in  red  and  black.  It  feeds  freely  upon 
a  variety  of  plants,  but  is  most  destructive  to  cabbages.  Its 
life  history  is  very  similar  to  that  of  the  Squash  Bug.  The 
barrel-shaped  eggs  are  laid  in  clusters,  commonly  in  two 
rows  of  six  eggs  each.  They  soon  hatch  into  small  flat- 
tened bugs  that  bear  a  general  resemblance  to  the  adults, 
although,  of  course,  they  have  neither  wings  nor  wing 
pads.  These  young  nymphs  suck  the  sap  from  the  leaves 
through  their  pointed  beaks,  and  during  the  next  month 
shed  their  skins  four  or  five  times  before  they  reach 
maturity.  There  are  several  broods  every  year,  and  the 
winter  is  commonly  passed  in  the  adult  condition. 

As  the  Harlequin  Cabbage  Bugs  come  from  their  winter 
quarters  very  early  and  are  readily  attracted  to  mustard, 
turnips,  and  other  plants,  it  is  generally  practicable  to  use 
these  as  trap  crops.  By  planting,  for  example,  a  few  rows 
of  mustard  in  the  cabbage  field,  the  bugs  will  be  attracted  to 
these  plants  and  may  be  readily  destroyed  together  with 
the  plants  by  spraying  with  pure  kerosene.  The  field  will 
then  be  comparatively  free  from  the  pest,  and  those  that 

come  later  may  be  subdued  by  hand  picking. 

? 

CICADAS  OR  HARVEST  FLIES 

The  Harvest  Flies  or  Cicadas  (Cicadidae)  are  the  largest 
insects  belonging  to  the  suborder  Homoptera.  Every  one 
has  heard  during  the  hot  days  of  midsummer  and  early 


78       FARM  FRIENDS  AND  FARM  FOES 

autumn,  the  strange,  shrill  noise  of  the  common  Harvest 
Fly,  or  Dog-day  Cicada.  This  insect  is  present  everywhere, 
and  its  curious  song  is  one  of  the  most  striking  and  charac- 
teristic of  summer  sounds. 

The  most  famous  member  of  this  family,  however,  is  the 
strangely  interesting  Periodical  Cicada  or  Seventeen-year 
Locust.  The  adults  of  these  insects  appear  in  certain  lo- 
calities at  intervals  of  either  thirteen  or  seventeen  years. 
They  may  then  be  exceedingly  numerous.  At  such  times 
they  deposit  eggs  in  the  twigs  of  trees.  These  eggs  soon 
hatch  into  strange  little  larvae  that  drop  to  the  ground  and 
work  their  way  through  the  soil  until  they  find  some  roots 
of  trees  or  shrubs.  Here  they  remain  feeding  and  growing 
very  slowly  for  a  long  period  of  years.  As  already  indi- 
cated, in  some  regions  they  complete  their  development  in 
thirteen  years  and  in  others  in  seventeen  years.  By  the 
end  of  this  long  time,  the  little  larvae  have  become  quite 
large,  and  are  of  the  shape  shown  in  the  lower  illustration 
on  the  next  page.  They  now  come  to  the  surface  of  the 
soil  and  crawl  up  the  trunk  of  some  tree  or  shrub,  where 
they  emerge  as  adult  cicadas.  These  are  able  to  make  a 
curious  shrill  noise,  somewhat  similar  to  that  of  the  Dog- 
day  Cicada,  although  in  both  species  the  ability  to  sing  is 
confined  to  the  males.  When  the  insects  are  very  abun- 
dant, the  sound  may  become  almost  deafening. 

LEAF  HOPPERS 

If  with  a  close-meshed  insect  net,  you  sweep  diligently 
a  few  yards  of  meadow  or  pasture  land,  it  is  probable  that 
the  most  abundant  insects  you  find  in  the  net  will  be  the 
small,  flattened,  quick-jumping  Leaf  Hoppers  (Jassoidea). 
These  insects  vie  with  the  plant  lice  in  their  enormous 
numbers.  They  are  likely  to  be  present  in  any  region. 


PERIODICAL 
CICADA 


Adult  emerging 
from  pupa 


Full-grown  pupa 


. 

Iflr 

/Wl 
'  T  % 


8o  FARM   FRIENDS   AND   FARM   FOES 

So  many  of  them,  however,  live  concealed  in  grass  lands 
that  most  people  have  little  knowledge  of  their  abundance. 
They  are  nearly  all  quite  small  insects,  but  doubtless  do  a 
great  deal  more  damage  than  is  commonly  attributed  to 
them.  They  suck  the  sap  from  practically  all  kinds  of 
grains  and  grasses,  and  many  infest  trees, 
snru^s»  and  other  plants.  They  are 
cl°sely  related  to  the  Tree  Hoppers  found 

on  the  twigs  of  trees. 
TREE  HOPPERS  _,,      ,.f     ,  .  L  f  .          .    . 

The  life  history  of  many  species  of  the 

grass-feeding  Leaf  Hoppers  has  been  carefully  studied. 
The  eggs  are  laid  in  autumn  in  the  grass  blades  and  remain 
unhatched  through  the  winter.  In  spring  they  hatch  into 
tiny  nymphs  or  larvae  that  suck  the  sap  from  new  grass 
blades  and  gradually  develop  into  adult  Leaf  Hoppers. 
During  this  process  they  generally  molt  or  cast  their  skins 
four  or  five  times,  reaching  maturity  early  in  summer. 
There  seem  generally  to  be  at  least  two  broods  of  the  grass- 
feeding  Leaf  Hoppers  in  a  season. 

In  cases  of  great  injury  by  these  grass-feeding  Leaf 
Hoppers,  it  may  be  worth  while  to  burn  over  the  areas 
most  badly  infested  in  winter  or  early  spring,  and  thus  de- 
stroy the  winter  eggs.  It  has  also  been  found  that  vast 
numbers  of  the  adult  insects  may  be  killed  by  the  use  of  a 
broad  pan  similar  to  the  hopper-dozer  often  employed  to 
destroy  grasshoppers.  If  this  pan  is  covered  with  kero- 
sene, tar,  or  some  similar  substance,  the  insects  will  be 
caught  and  killed. 

Many  crop  pests  are  found  among  the  Leaf  Hoppers 
that  feed  upon  vines,  shrubs,  and  trees.  The  Grape  Leaf 
Hopper  is  one  of  the  most  destructive  and  widely  distrib- 
uted of  these.  Its  life  history  has  been  carefully  worked 
out  in  New  York,  where  it  has  been  found  that  the  adult 


HEMIPTERA:  THE  TRUE  BUGS  81 

insects  spend  the  winter  under  leaves  and  rubbish,  or  in 
some  similar  shelter.  They  come  forth  rather  early  in  the 
spring  and  feed  for  two  or  three  weeks  upon  the  leaves  of 
raspberries,  strawberries,  and  other  plants.  Early  in  May, 
when  the  leaves  of  the  grapes  appear,  these  adult  Leaf 
Hoppers  fly  to  the  vineyards  and  attack  the  developing 
foliage.  They  continue  here  for  many  weeks.  The  fe- 
males deposit  their  small,  whitish  eggs  in  the  green  tissues 
of  the  blades  of  the  leaves,  several  eggs  being  inserted 
side  by  side. 

A  fortnight  later  these  eggs  hatch  into  small  larvae  or 
nymphs  that  also  suck  the  sap  from  the  leaves  and  grad- 
ually develop,  passing  through  five  molts  before  they  be- 
come mature.  These  young  nymphs  are  able  to  run  over 
the  surface  of  the  leaves,  but  they  do  not  jump  as  do  the 
fully  developed  Leaf  Hoppers.  They  reach  maturity  dur- 
ing the  latter  part  of  the  summer  and  continue  present 
until  October,  when  they  seek  shelter  for  the  winter. 
There  is  thus  normally  but  one  brood  in  a  year,  although 
in  more  southern  regions  there  are  probably  two  broods. 

The  most  effective  means  of  combating  this  insect  are 
burning  over  the.  places  of  hibernation,  destroying  the 
nymphs  with  a  solution  of  whale-oil  soap  at  the  rate  of  one 
pound  to  ten  gallons  of  water,  and  trapping  the  adults  upon 
sticky  shields  held  temporarily  beside  the  vines. 

The  Apple-tree  Leaf  Hopper  is  another  widely  distrib- 
uted destructive  species.  Examples  of  this  may  be  found 
on  the  under  side  of  apple  leaves  at  almost  any  time  during 
the  season.  The  Rose  Leaf  Hopper  is  another  form  that 
may  practically  always  be  found  upon  rosebushes,  where 
the  characteristic  result  of  Leaf  Hoppers'  injury  may  be 
seen  in  the  whitened  spots  on  the  upper  surface  of  the 
leaf. 


82  FARM  FRIENDS  AND   FARM  FOES 

JUMPING  PLANT  LICE 

The  Jumping  Plant  Lice  (Psyllidae)  are  few  in  number  of 
species,  and  with  the  exception  of  the  Pear  Psylla  are  of 
comparatively  little  economic  importance.  This  Pear  Psylla, 
however,  often  becomes  a  very  serious  pest,  attacking  pear 
trees  in  overwhelming  numbers,  and  sucking  out  the  sap 
to  such  an  extent  as  to  cause  great  injury.  The  adult 
insect,  which  is  only  about  the  size  of  an  ordinary  plant 
louse,  passes  the  winter  on  the  bark  of  pear  trees,  commonly 
more  or  less  concealed  within  crevices.  They  deposit  their 
eggs  very  early  in  spring,  especially  about  the  buds  or 
upon  the  unfolding  leaves.  In  two  weeks  or  so,  the  eggs 
hatch  into  tiny  larvae  which  attack  the  petioles  of  the 
leaves  as  well  as  their  general  surface.  In  about  a  month 
each  larva  reaches  maturity,  having  molted  five  times 
during  the  process.  There  are  several  broods  each  year, 
the  number  doubtless  varying  with  the  locality. 

Like  the  aphides,  these  insects  secrete  a  large  amount 
of  the  so-called  honey  dew,  which  consists  chiefly  of  the 
sap  of  the  plant  that  has  passed  through  the  bodies  of  the 
insects.  Where  a  pear  tree  is  badly  infested,  this  honey 
dew  covers  the  leaves,  often  collecting  in  large  drops, 
which  are  believed  to  act  sometimes  as  lenses  in  condensing 
the  sun's  rays  so  as  to  burn  the  foliage  beneath.  Upon 
this  honey  dew,  there  also  develops  a  black  fungus  that 
soon  gives  the  leaves  and  fruit  of  the  infested  tree  a  strange 
blackened  appearance. 

SCALE  INSECTS  OR  COCCIDS 

The  strange  Scale  Insects  or  Coccids  (Coccidae)form  one 
of  the  most  important  groups  of  the  Homoptera.  Many 
of  these  are  commonly  known  as  Bark  Lice,  because  they 


HEMIPTERA:  THE  TRUE  BUGS 


are  found  so  frequently  upon  the  bark  of  trees.  If  you 
examine  the  twigs  or  leafy  branches  of  some  apple  trees, 
you  will  probably  find  what  look  like  miniature  oyster 
shells  upon  the  bark.  These  are  ex- 
amples of  the  Oyster-shell  Scale.  If 
you  will  carefully  pry  up  one  of  these 
tiny  scales  and  look  at  its  under  side 
with  a  lens,  you  will  probably  find  a 
large  number  of  minute  oval  eggs. 
Early  in  summer,  these  eggs  hatch  into 
tiny  insects  that  wander  over  the  sur- 
face of  the  young  bark.  In  a  day  or 
two,  they  fix  themselves  in  one  place 
by  inserting  their  beaks  into  the  tissues 
and  sucking  out  the  sap,  where  they  re- 
main and  gradually  develop  their  scaly 
covering. 

One  of  the  most  destructive  insects 
ever  introduced  into  America  belongs 
to  this  family.  It  is  the  notorious  San 
Jose  Scale,  a  pest  that  during  recent 
years  has  attracted  more  attention  from 
fruit  growers  than  any  other  insect. 
It  is  especially  dangerous  because  its  presence  is  difficult 
to  detect  until  it  becomes  sufficiently  abundant  to  injure  or 
kill  the  infested  tree.  It  then  appears  as  a  curious  scaly 
crust  on  the  bark.  When  only  a  few  are  present,  they  are 
difficult  to  find,  as  they  are  simply  small  circular  spots  of 
much  the  same  color  as  the  bark,  plainly  seen  only  through 
a  magnifying  glass. 

The  appearance  of  the  individual  scales  is  well  shown 
in  the  pictures  on  the  next  page.  Each  scale  is  a 
small  circular  object,  closely  attached  to  the  bark,  not  more 


SCALE  INSECTS  ON 
ROSE 


Much   Maqnified 


m 


4 


LARVA 


SAN  JOSE  SCALE 

INFESTED  PEAR  Twic 

Magnified 


HEMIPTERA:  THE  TRUE  BUGS 


than  one  sixteenth  of  an  inch  in  diameter,  having  a  dark 
raised  point  near  the  center.  At  first  these  scales  are 
likely  to  be  scattered  here  and  there  over  the  bark,  but  as 
they  increase  in  numbers,  they  are  found  nearer  together, 
touching  or  overlapping  one  another.  Finally,  when  they 
become  very  abundant,  they  make  a  thick  scurfy  layer,  of 
a  grayish  color  that  obscures  the  natural  color  of  the  bark 
and  is  easily  rubbed  off  with 
a  knife.  The  presence  of 
such  a  layer  indicates  that 
the  sap  from  the  bark  is  be- 
ing sucked  out  by  millions 
of  the  insects,  and  that  the 
health  of  the  tree  is  being 
seriously  impaired. 

The  young  scales  that  live 
through  the  winter  develop 
in  early  spring  into  mature 
insects,  and  each  of  the  fe- 
males may  givebirth  to  about 
four  hundred  young.  These  are  tiny  yellow  creatures  that 
crawl  around  for  about  a  day  before  they  finally  fasten 
themselves  to  the  bark  by  inserting  their  curious  beaks  to 
suck  the  sap.  They  then  begin  to  secrete  the  scale  which 
is  so  characteristic  of  this  family  of  insects.  The  scale  is 
composed  of  white  waxy  threads  secreted  by  the  skin  of 
the  larvae,  which  mat  together  to  form  a  rather  dense 
covering.  This  whitish  scale  turns  gray  or  even  almost 
black  within  a  few  days.  The  female  scales  are  always 
wingless,  but  the  male  scales  develop  into  active  two-winged 
insects  which  are  able  to  fly  about. 

When  the  San  Jose  Scale  appears  upon  older  trees,  it  is 
most  likely  to  be  found  on  twigs  and  smaller  limbs,  but 


BLACK  SCALE 


86       FARM  FRIENDS  AND  FARM  FOES 

upon  young  trees  it  may  occur  over  the  whole  surface  of 
the  bark.  It  does  not  confine  its  attacks  to  the  bark,  how- 
ever, for  leaves  and  fruit  are  often  infested.  Upon  these, 
as  well  as  upon  young  bark,  there  is  frequently  a  very 
characteristic  purplish  ring  around  each  scale.  When  the 
leaves  are  infested,  the  insects  are  especially  likely  to  be 
found  along  the  midrib. 

This  scale  has  commonly  been  introduced  into  new 
localities  by  means  of  young  trees  from  nurseries.  There 
are  now  rigid  inspection  laws  in  nearly  all  the  states  to 
prevent  the  further  distribution  of  the  pest  in  this  way. 
The  most  effective  remedy  so  far  discovered,  is  that  of 
spraying  in  late  autumn  with  a  miscibleoil  or  a  lime-sulphur 
wash.  As  is  so  often  the  case,  the  use  of  this  lime-sulphur 
wash  has  been  found  to  have  additional  advantages  in  de- 
stroying other  insects  and  in  preventing  various  fungous 
diseases. 

The  Cottony  Maple  Scale  is  one  of  the  most  distinctive 
members  of  the  great  family  of  Bark  Lice.  It  may  be 
found  in  vast  numbers,  especially  in  the  Middle  Western 
states,  upon  the  twigs  of  the  silver  maple,  and  is  easily 
recognized  by  the  mass  of  cottony  tufts  which  are  found 
beneath  each  of  the  darker-colored  scales.  Early  in  sum- 
mer great  numbers  of  eggs  are  deposited  inside  of  these 
cottony  masses.  About  three  thousand  eggs  commonly 
occur  beneath  each  scale.  In  June  or  July  these  eggs 
hatch  into  tiny  larvae  that  wander  over  the  leaves  and  soon 
fix  themselves,  inserting  their  beaks  to  suck  the  liquid 
from  the  tissues.  Here  they  continue  to  develop  until 
shortly  before  the  time  for  the  leaves  to  fall.  By  this  time, 
the  males  mature  into  small  winged  insects  that  are  able 
to  desert  the  leaves  and  fly  about.  The  females,  however, 
crawl  from  the  leaves  to  the  bark  of  the  neighboring  twigs, 


HEMIPTERA:   THE  TRUE  BUGS  87 

upon  which  they  fix  themselves  and  secrete  a  larger  scale. 
They  remain  on  the  twigs  through  the  winter,  and  the 
following  spring  complete  their  growth,  produce  the 
cottony  mass  within  which  they  lay  their  eggs,  and  finally 
die.  There  is  thus  but  one  brood  each  year.  Fortunately 
this  insect,  as  well  as  most  other  members  of  this  family,  is 
commonly  kept  in  check  by  its  parasitic  and  other  enemies. 
The  most  important  of  these  are  small,  black,  four-winged 
chalcid  flies  and  various  species  of  ladybird  beetles. 

THE  APHIDES  OR  PLANT  LICE 

From  the  point  of  view  of  their  destructiveness,  the 
Aphides  or  Plant  Lice  form  one  of  the  most  important 
families,  not  only  of  the  true  bugs,  but  .of  all  insects. 
During  very  recent  years  a  single  species  affecting  grain 
has  caused  a  loss  of  more  than  a  million  dollars  in  one 
state  in  a  single  year.  There  are  a  great  many  species  of 
these  little  pests,  of  which  the  Green  Flies  of  house  plants 
are  familiar  examples.  They  infest  nearly  all  kinds  of 
crops,  sucking  the  sap  through  their  pointed  beaks  and 
often  causing  enormous  losses. 

The  life  histories  of  the  various  species  of  Aphides  are 
quite  similar.  A  good  illustration  is  found  in  that  of  the 
Spring-grain  Aphis  which  has  attracted  much  attention  on 
account  of  its  damage  to  grain  crops.  Pictures  of  its  vari- 
ous stages  much  magnified  are  shown  on  the  next  page. 
In  many  localities,  it  has  been  known  as  the  "Green  Bug." 
It  is  especially  abundant  in  the  more  southern  rather  than 
the  far  northern  states. 

Under  normal  conditions  the  Spring-grain  Aphis  passes 
the  winter  in  the  condition  of  the  egg,  attached  to  leaves  or 
stalks  of  various  grains  and  grasses.  Early  in  the  spring, 
these  eggs  hatch  into  small  plant  lice  that  suck  the  sap 


88 


FARM  FRIENDS  AND   FARM  FOES 


from  the  food  plants  and  become  full-grown  in  a  very 
short  time,  possibly  a  week  or  ten  days.  All  of  these 
insects  that  thus  hatch  from  the  winter  eggs  are  what  are 
known  as  viviparous  females,  because  they  are  able  to  give 


PupA 


LARVA 
SPRING  GRAIN-APHIS 

[Redrawn  from  Webster] 


WiNGLESS 

FEMALE 


WINGED 


FEMALE 


birth  to  living  young.  Each  insect  produces  a  large 
number  of  these  young  plant  lice  of  the  second  generation, 
and  these  in  turn  very  quickly  mature  and  give  birth  to  a 
third  generation.  This  method  of  reproduction  continues 
throughout  the  spring,  summer,  and  early  autumn.  On 
account  of  the  rapid  growth  and  of  the  large  number  of 
young  produced  by  each  of  the  viviparous  females,  the 
insect  is  able  to  multiply  with  astounding  rapidity.  . 
When  the  food  plant  is  green  and  succulent,  nearly  all 


HEMIPTERA:   THE   TRUE  BUGS  89 

the  aphides  are  wingless  forms,  but  when  for  any  reason 
the  condition  of  the  food  plant  is  less  favorable  to  the 
development  of  the  plant  lice,  large  numbers  of  winged 
viviparous  females  are  developed.  These  are  often  called 
winged  migrants,  because  so  many  of  them  fly  away  to  other 
fields  where  they  settle  upon  new  plants  and  there  give 
birth  to  living  young.  In  this  way  the  insect  commonly 
spreads  from  field  to  field,  and  when  it  has  wintered  in  the 
South,  it  may  gradually  spread  northward  to  infest  new 
localities. 

When  the  grain  crop  ripens,  the  aphides  usually  migrate 
to  various  kinds  of  grasses,  where  they  continue  to  develop 
throughout  the  summer,  and  migrate  back  again  in  autumn 
to  fields  of  young  grain.  In  these  fields  they  continue  to 
reproduce  in  the  same  viviparous  manner  until  the  approach 
of  cold  weather.  At  this  time  a  sexual  generation  is  devel- 
oped, the  males  commonly  being  winged,  while  the  females 
are  wingless.  The  winter  eggs  are  laid  by  these  females, 
and  thus  the  yearly  cycle  is  completed. 

When  the  winters  are  mild,  it  very  often  happens  that 
this  Grain  Aphis  is  able  to  continue  to  develop  through- 
out the  winter  in  its  viviparous  condition,  so  that  in  a  given 
locality  we  may  have  it  passing  the  winter  both  in  the 
egg  state  and  in  that  of  various  ages  of  viviparous  females. 
It  is  under  such  conditions  that  the  greatest  damage  is 
likely  to  occur,  especially  because  of  the  fact  that  the  in- 
sects are  able  to  thrive  and  multiply  in  a  lower  temperature 
than  is  favorable  to  the  development  of  the  tiny  parasitic 
flies  that  commonly  keep  them  in  check. 

An  even  more  interesting  life  history  is  that  of  a  closely 
related  plant  louse  known  as  the  European  Grain  Aphis. 
This  insect  is  abundant  and  very  generally  distributed  in 
America.  Its  special  point  of  interest  is  that  it  develops 


90  FARM  FRIENDS  AND   FARM  FOES 

in  summer  on  various  grains  and  grasses,  and  migrates  in 
autumn  to  apple  trees,  where  the  winter  eggs  are  laid. 
Consequently,  when  we  attempt  to  follow  its  history  through 
the  year,  we  may  begin  in  early  spring  with  these  eggs 
upon  the  buds  and  bark  of  apple  twigs,  with  this  summary 
as  a  result :  — 

In  early  spring  the  eggs  hatch  into  small  aphides  that 
crawl  at  once  to  the  developing  buds  where  they  begin  to 
suck  the  juices  of  the  unfolding  leaves.  In  a  few  days, 
this  first  generation  from  the  egg,  often  called  the  stem- 
mothers,  begin  giving  birth  to  living  young  that  also  suck 
the  sap  from  the  leaves  and  soon  become  mature.  In  this 
way,  four  or  five  generations  may  develop  on  the  apple  in 
spring.  A  large  proportion  of  the  later  generations  are 
winged  females,  which  fly  away  to  settle  upon  grasses  and 
grains  and  start  colonies  upon  these  host  plants.  Conse- 
quently these  are  called  winged  migrants.  As  a  rule,  all 
of  the  plant  lice  of  this  species  thus  desert  the  apple  before 
midsummer. 

The  winged  migrants  upon  grains  and  grasses  establish 
colonies  that  continue  to  increase  throughout  the  remain- 
der of  the  summer  upon  these  food  plants,  one  generation 
following  another  in  rapid  succession.  Rather  early  in 
autumn,  however,  a  generation  of  winged  females,  called 
the  return  migrants,  is  developed  from  the  grain  and  grass- 
feeding  colonies.  These  return  to  the  apple,  where  they 
give  birth  to  a  generation  of  wingless  egg-laying  aphides, 
by  which  the  winter  eggs  are  laid  upon  twigs. 

There  are  various  other  species  of  aphides  which  may  be 
found  upon  the  leaves  of  the  apple.  The  presence  of  these 
other  species  has  rendered  the  working  out  of  the  life  his- 
tory of  this  European  Grain  Aphis  a  much  more  difficult 
problem  than  might  at  first  appear. 


HEMIPTERA:   THE   TRUE   BUGS 


91 


EGGS 
APPLE  APHIS 


It  was  formerly  supposed  that  to  a  large  extent  each 
kind  of  plant  was  subject  to  attack  by  a  special  kind  of 
plant  louse,  but  after  careful  studies  were  made  of  the 
structure  and  life  histories  of  the  plant  lice,  it  was  found 
that  very  often  a  single  species 
of  the  insects  may  attack  sev- 
eral species  of  plants.  One  of 
the  most  striking  examples  of 
this  ability  to  live  upon  various 
host  plants  is  that  of  the  Melon 
Aphis,  which  infests  an  extraor- 
dinary variety  of  host  plants. 
These  include  vegetable,  field, 
and  fruit  crops,  as  well  as  many 
cultivated  flowers  and  an  extraor- 
dinary number  of  weeds  and 
other  wild  plants.  It  has  been 
known  by  such  common  names 
as  Cotton  Aphis,  Orange  Aphis, 
and  Dock  Aphis.  It  is  so  com- 
monly destructive  to  melons,  cu- 
cumbers, and  related  plants  that 
it  is  now  generally  called  the 
Melon  Aphis,  although  in  cotton-growing  regions  it  is 
known  as  the  Cotton  Aphis. 

The  life  history  of  this  insect  is  not  very  different  from 
that  of  the  Spring-grain  Aphis  already  described.  The 
winter  is  passed  both  in  the  egg  state  and  in  that  of  the 
viviparous  females.  Reproduction  begins  early  in  spring 
and  continues  throughout  the  season,  the  insects  multiply- 
ing with  marvelous  rapidity  and  migrating  from  time  to  time 
from  one  food  plant  to  another.  The  ability  of  the  species 
to  develop  upon  so  great  a  variety  of  hosts  renders  it 


FARM   FRIENDS   AND   FARM   FOES 


easy  for  the  migrating  females  to  find  suitable  food,  and  it 
also  renders  the  pest  very  difficult  to  fight  successfully. 

ANTS  AND  APHIDES 

One  of  the  most  interesting  things  about  the  aphides  is 
their  relation  to  various  kinds  of  ants.  If  you  look  at  a 
colony  of  plant  lice  upon  almost  any  tree  or  shrub,  you  will 
probably  find  at  least  one  kind  of  ant  wandering  around 
among  the  aphides,  and  very  likely  you  will  find  a  regular 

procession  of  ants  go- 
ing up  and  down  the 
trunk  of  the  tree  or 
shrub.  If  you  watch 
one  of  these  ants  care- 
fully, you  will  probably 
see  it  find  a  plant  louse, 
touch  it  with  the  feelers 
or  antennae  and  very 
likely  lap  up  a  drop  of 
liquid  exuded  by  the 
aphis,  for  these  ants 

visit  the  plant  lice  to  obtain  the  liquids  that  pass  through 
their  bodies.  In  consequence,  the  plant  lice  are  sometimes 
referred  to  as  the  milch  cows  of  the  ants. 

There  are  many  strange  and  interesting  things  to  be  found 
out  concerning  the  relations  of  the  ants  and  the  aphides. 
To  a  very  large  extent,  many  species  of  aphides  find  friendly 
helpers  in  the  ants.  One  of  the  most  interesting  examples 
of  this  is  the  case  of  the  Corn-root  Aphis,  an  insect  often 
very  destructive  to  corn  crops  in  the  Mississippi  Valley. 

This  Corn-root  Aphis  is  constantly  attended  by  a  small 
brown  ant  that  burrows  out  tunnels  along  the  corn  roots  in 
order  that  the  plant  lice  may  have  a  place  to  live.  As  the 


ANT  ATTENDING  APHIDES  UPON  A  WILLOW 
TWIG 


HEMIPTERA:    THE  TRUE  BUGS  93 

numbers  of  the  plant  lice  increase,  the  ants  extend  the 
burrows  to  provide  for  them.  The  ants  continue  thus  to 
look  after  the  needs  of  the  aphides  throughout  the  summer 
months.  In  autumn,  however,  a  still  more  interesting  thing 
takes  place,  for  at  this  time  an  egg-laying  brood  of  aphides 
is  developed  and  the  small  blackish  eggs  are  taken  by  the 
ants  far  down  in  their  underground  nests,  where  the  eggs 
are  cared  for  throughout  the  winter.  When  the  eggs  hatch 
early  the  following  spring,  the  young  plant  lice  are  carried 
by  the  ants,  generally  to  the  roots  of  some  grass-like  weed, 
there  to  start  the  new  season's  brood,  which  will  be  trans- 
ferred later  to  the  roots  of  the  young  corn  plants. 

In  a  case  like  that  of  the  Cornroot  Aphis,  where  the 
eggs  of  the  insect  pass  the  winter  in  the  cornfield,  rotation 
of  crops  is  the  best  means  of  reducing  injury  by  the  pest. 
It  is  fortunate  that  there  are  great  numbers  of  enemies  of 
aphides  in  general,  for  otherwise  it  would  probably  be  im- 
possible to  grow  many  crops  now  produced.  Many  birds 
feed  freely  upon  the  eggs  and  later  stages  of  aphides,  while 
vast  numbers  of  predaceous  and  parasitic  insects  develop  at 
their  expense.  The  insecticides  that  are  most  effective  in 
destroying  plant  lice  are  kerosene  emulsion,  whale-oil  soap, 
and  various  decoctions  and  extracts  from  tobacco  stems. 


ELM  LEAF  AFFECTED  BY  APHIDES 


94  FARM  FRIENDS  AND   FARM  FOES 

OBSERVATIONS  FOR  PUPILS 
SQUASH  BUG 

1 .  To  what  extent  are  these  insects  troublesome  in  your  locality  ? 

2.  What  plants  do  they  attack  ? 

3.  What  methods  are  used  to  kill  them  ? 

4.  Try  placing  shingles  or  small  boards  about  the  hills  to  see  if  the 
bugs  seek  their  shelter  at  night. 

5.  Make  a  drawing  of  the  Squash  Bug  for  your  insect  booklet. 
Read :  - 

The  Common  Squash  Bug,  U.  S.  Bureau  of  Entomology,  Circular  39. 

HARLEQUIN  CABBAGE  BUG 

1.  Is  this  insect  common  in  your  region? 

2.  What  plants  have  you  known  it  to  feed  upon? 

3.  Have  you  seen  the  eggs?     Where  were  they  laid? 

4.  What  remedies  have  you  known  to  be  used  against  Harlequin 
Cabbage  Bugs  ? 

CICADAS  OR  HARVEST  FLIES 

1.  Have  your  ever  known  an  outbreak  of  the  Periodical  Cicada?    If 
not,  ask  your  friends  about  such  outbreaks. 

2.  Do  you  know  the  song  of  the  common  cicada?     How  often  do 
you  hear  it?     Is  it  more  likely  to  be  heard  on  hot  or  cool  days?     Did 
you  ever  see  one  of  the  cicadas  on  a  tree  ? 

3.  Read  some  of  these  accounts  of  cicadas  :  — 

American   Insects,   pages    166-168.      Stories    of  Insect  Life,   Second    Series, 
pages  1-5. 

LEAF  HOPPERS 

1.  Look  on  the  under  sides  of  the  leaves  of  trees,  shrubs,  and  herbs 
to  find  leaf  hoppers.     Are  they  of  different  sizes  and  colors?     You  can 
get  many  of  them  by  sweeping  grasses  and  herbage  with  an  insect  net 
or  by  beating  branches  over  an  open  inverted  umbrella. 

2.  You  will  readily  find  the  earlier  stages  of  the  leaf  hoppers  on  many 
leaves.     Are  the  wings  developed?     Can  the  young  hoppers  jump  like 
the  adults  ? 


HEMIPTERA:   THE   TRUE   BUGS 


95 


BARK  LICE  OR  SCALE  INSECTS 

1.  Look  on  apple  twigs  for  the  characteristic  scales  of  the  Oyster- 
shell  Scale.     Pry  up  a  scale  and  look  on  the  under  side  with  a  lens. 
In  the  fall,  winter,  or  early  spring  you  are  likely  to  find  many  eggs. 

2.  Examine  various  fruit  trees,  especially 
peaches,  plums,  and  pears,  for  the  San  Jose 
Scale.      If  found,  learn  whether  the  trees 
have  been   sprayed  to  destroy  them.     In 
autumn  the  scales  are   likely  to  be  found 
upon  the  fruits. 

3.  Examine  other  trees  and  shrubs  for 
other  scale  insects.     In  order  to  learn  their 
names,  send  such  as  you  find  to  the  Bureau 
of  Entomology,  U.  S.  Department  of  Agri- 
culture, Washington,  D.C.,   with   a  letter 
telling  on  what  plant  you  found  them. 

APHIDES  OR  PLANT  LICE 

1.  You  generally  can  find  these  insects 
with  very  little  trouble.    Look  on  the  leaves 
of  apple  or  other  fruit  trees,  or  on  willows  or 
other  trees.      Look  also  on  the  leaves  of 
flowers  and  vegetables.    Do  all  the  different 
kinds  of  aphides  you  find  look  alike? 

2.  In  fall  and  winter  look  on  the  bark 
of  the  willow  branches  and  about  the  buds 
of  apple  trees  to  find  the  winter  eggs  of  the 

aphides.    Examine  them  through  a  lens  and  make  a  sketch  for  your  insect 
booklet. 

3.  Many  aphides  live  in  gall-like  modifications  of  the  leaves.     Make 
sketches  of  such  of  these  as  you  can  find. 

4.  Read  one  or  more  of  these  references  :  — 

American  Insects,  pages  171-176.     Life  Histories  of  American    Insects,  pages 
209-247. 


CICADA  EMERGING  FROM 
NYMPH  SKIN 


CHAPTER   VIII 


The  Butterflies  and  Moths 

THE  great  order  of  insects  to  which  the  butterflies  and 
moths  belong  is  called  Lepidoptera,  a  word  meaning  scale- 
winged.  This  name  was  given  to  the  group  because  each 
of  the  beautiful  wings  with  their  varied  colors  and  markings 
is  composed  of  a  thin  membrane,  to  which  are  attached 

vast  numbers  of  tiny  scales  over- 
lapping one  another,  much  like  the 
shingles  of  a  house.  The  insects 
of  this  order  have  sucking  mouth 
parts  and  two  pairs  of  wings.  The 
transformations  are  complete.  The 
period  of  growth  and  feeding  is 
that  of  the  larva  or  caterpillar,  the 
adults  eating  only  the  nectar  of 
flowers  or  similar  substances,  or, 
in  some  cases,  taking  no  food  at 
all. 

This  order  includes  a  large  num- 
ber of  species,  varying  greatly  in 
size  and  habits.  Some  of  the  moths 
are  so  tiny  as  to  be  barely  visible 
to  the  unaided  eye,  while  others  are  so  large  and  conspic- 
uous as  to  attract  attention  at  considerable  distances.  By 
far  the  largest  proportion  of  the  species  feed  in  the  larval 
state  upon  the  tissues  of  plants,  and  consequently  a  great 
many  injurious  insects  are  found  in  the  order. 

96 


PROMETHEA  MOTH  COCOON 


THE   BUTTERFLIES   AND   MOTHS  97 

THE  BUTTERFLIES 

The  highest  group  of  the  Lepidoptera  is  the  great  super- 
family  to  which  the  butterflies  belong ;  this  is  commonly 
called  the  Papilionina.  This  includes  four  distinct  families 
which  need  not  be  considered  specifically  here. 

The  butterflies  as  a  group  are  day-flying  insects,  with 
knobbed  antennae  or  "feelers,"  small  bodies,  and  compara- 
tively large  wings.  The  caterpillars  do  not  spin  cocoons, 
changing  to  the  pupa  state  as  naked  chrysalids,  although 
often  there  is  a  loop  of  silk  over  the  shoulders  to  hold  the 
chrysalis  in  position.  These  caterpillars  have  three  pairs 
of  true  legs  and  five  pairs  of  prolegs. 

A  familiar  example  of  the  life  history  of  a  butterfly  is 
found  in  the  common  Cabbage  Worm,  the  adult  of  which 
is  the  common  white  butterfly,  with  black  spots  upon  the 
wings,  which  is  to  be  seen  flying  about  gardens  throughout 
the  summer.  These  butterflies  lay  eggs  upon  the  cabbage 
leaves.  The  eggs  soon  hatch  into  small  greenish  larvae 
that  feed  upon  the  tissues  of  the  leaf  for  a  few  weeks, 
molting  or  casting  their  skins  four  or  five  times  during  this 
period.  When  full  grown,  they  find  some  sheltering  leaf, 
stone,  or  board,  beneath  which  they  change  to  the  chrysalis 
state,  to  emerge  a  short  time  later  as  adult  butterflies. 

While  as  a  group  the  butterflies  have  by  no  means  as 
many  injurious  species  as  have  the  various  groups  of  moths, 
a  number  of  rather  destructive  insects  belong  to  it.  One 
of  the  most  widespread  of  these  is  the  Black  Swallow-tail 
or  Asterias  Butterfly,  the  larvae  of  which  feed  upon  the 
leaves  of  celery,  carrots,  parsnips,  and  various  other  mem- 
bers of  the  parsley  family.  These  caterpillars  are  green, 
marked  with  black,  and  may  very  commonly  be  found  upon 
the  garden  plants  mentioned.  Another  species,  which  is 


98 


FARM  FRIENDS  AND  FARM  FOES 


often  destructive,  is  the  Mourning  Cloak  Butterfly,  the 
caterpillars  of  which  frequently  defoliate  willow,  poplar, 
and  elm  trees,  so  that  in  some  localities  they  are  called  the 
Spiny  Elm  Caterpillars. 

An  even  more  generally  destructive  butterfly  is  the  larg- 
est of  our  North  American  forms,  called  the  Cresphontes 
Butterfly.  This  is  a  Southern  species,  being,  however, 
widely  distributed  as  far  north  as  Massachusetts,  New 


ORANGE-DOG  CATERPILLARS 

York,  and  Illinois.  Throughout  the  orange-growing  re- 
gions, the  caterpillars  are  commonly  known  as  "  Orange- 
dogs,"  because  they  feed  so  largely  upon  the  leaves  of 


THE   BUTTERFLIES   AND   MOTHS  99 

orange  trees,  being  especially  destructive  to  young  plants 
in  the  nursery.  They  are  curious-looking  caterpillars,  and 
doubtless  their  unusual  appearance,  possibly  suggestive  of 
a  watchdog,  has  given  rise  to  the  common  name. 

Briefly  summarized,  the  life  history  of  the  Orange-dog 
Butterfly  is  this :  The  eggs  are  deposited  singly  upon  the 


BUTTERFLY  OF  ORANGE-DOG  CATERPILLAR  JUST  EMERGED  FROM  CHRYSALIS 

young  growth  of  the  orange,  generally  near  the  tips  of 
leaves  or  branches.  In  a  week  or  more  they  hatch  into 
tiny  caterpillars  that  feed  upon  the  tender  foliage.  When 
not  eating  they  rest  upon  the  lower  surface  of  the  leaves. 
In  about  a  week,  they  become  too  large  for  the  skin  with 
which  they  were  born,  and  they  molt  or  cast  their  skin, 
coming  forth  with  a  new  one  that  had  been  formed  beneath 


ioo  FARM   FRIENDS   AND   FARM   FOES 

the  old.  They  then  feed  again  for  a  week  or  so  before 
molting  for  the  second  time. 

These  processes  of  feeding  and  molting  are  commonly 
continued  for  four  or  five  weeks,  the  caterpillars  eating 
more  and  more  of  the  leaves  as  they  grow  older.  They  no 
longer  confine  themselves  to  the  succulent  young  leaves 
and  shoots.  A  single  insect  may  do  much  damage  to  a 
young  tree,  as  it  consumes  a  relatively  large  amount  of  the 
growing  tissues  of  the  plant.  When  full  grown  in  the 
caterpillar  stage,  the  insect  changes  to  the  chrysalis,  gen- 
erally attaching  itself  by  silken  threads  to  the  bark  of  a 
twig  or  branch  of  the  orange  tree.  The  chrysalis  takes  on 
the  same  general  coloring  as  the  surrounding  bark,  so  that 
it  becomes  decidedly  inconspicuous.  In  a  little  less  than 
a  fortnight  it  emerges  as  an  adult  butterfly. 

Like  the  caterpillars  of  the  other  Swallow-tail  Butter- 
flies, these  Orange-dogs  have  curious  yellowish  scent  organs, 
which  protrude  from  the  upper  surface  just  behind  the 
head.  When  the  caterpillar  is  disturbed,  these  give  forth 
a  very  disagreeable  odor,  which  is  believed  to  serve  as  a 
means  of  repelling  birds  and  possibly  other  enemies.  At 
any  rate,  good  observers  have  noticed  that  the  insect  is  not 
molested  by  birds,  although  it  is  known  to  be  subject  to 
attack  by  various  insect  parasites.  Each  female  butterfly, 
apparently,  is  able  to  deposit  four  or  five  hundred  eggs, 
and  one  of  the  interesting  ways  suggested  for  preventing 
the  injuries  of  the  caterpillars  is  to  shoot  the  butterflies 
upon  the  wing  with  cartridges  loaded  with  sand  or  small 
bird  shot. 

SPHINX  MOTHS 

A  beautiful  family  of  the  scale-winged  insects  is  that  of 
the  Sphinx  Moths  or  Sphingidae ;  these  are  commonly 


THE  BUTTERFLIES  Afrb  MOTHS  161 

called  Hawk  Moths.  They  are  characterized  by  having 
large  bodies,  with  small  wings  and  very  long  curious 
tongues,  which  sometimes  reach  a  length  of  five  or  six 
inches.  Nearly  all  of  them  fly  just  at  twilight,  rather  than 
during  the  day.  The  family  includes  a  large  number  of 
species,  several  of  which  are  injurious  to  cultivated  crops. 

Most  of  the  caterpillars  of  the  Hawk  Moths  have  the  habit 
of  assuming  during  the  day  a  curious  attitude,  with  the 
head  end  of  the  body  held  rigidly  erect  in  a  way  suggestive 
of  the  famous  Sphinx  of  Egypt.  To  this  is  doubtless  due 
their  common  name  of  Sphinx  Caterpillars.  A  familiar 
illustration  of  these  larvae  may  be  found  late  in  summer  on 
tomato,  potato,  tobacco,  and  related  plants,  for  the  common 
tomato  and  tobacco  worms  belong  to  this  group.  There 
are  really  two  species  of  these  tomato  worms,  one  being 
more  abundant  in  the  North,  and  the  other  in  the  South. 
When  full  grown  the  caterpillars  burrow  into  the  soil,  where 
they  change  to  brown  pupae,  and  early  the  following  sum- 
mer wriggle  to  the  surface  of  the  soil,  to  emerge  as  beauti- 
ful grayish  Hawk  Moths. 

Another  common,  widely-distributed  member  of  this 
family  is  the  Pandorus  Sphinx,  the  caterpillars  of  which 
are  often  injurious  to  grapevines  and  Virginia  creepers 
or  woodbines.  The  moth  is  large  and  beautiful,  exquisitely 
colored  in  greens  and  browns.  The  eggs  are  laid  early  in 
summer  upon  the  leaves  of  the  food  plant,  hatching  in  a 
few  days  into  small  sphinx  caterpillars  that  feed  and  molt 
for  several  weeks  before  becoming  full  grown.  They  are 
then  three  or  four  inches  long,  and  the  thickness  of  a  man's 
finger.  They  now  crawl  to  the  ground  and  burrow  into 
the  soil  a  short  distance,  where  they  change  to  pupae,  to 
remain  until  the  following  season,  when  they  emerge  as 
moths. 


102 


FARM  FRIENDS   AND   FARM   FOES 


SILK-SPINNING  MOTHS 

One  of  the  most  important  groups  of  the  Lepidoptera 
is  that  of  the  silk-spinning  moths  (Bombycinae),  of  which 
the  most  famous  is  the  silkworm  of  commerce.  As  a  rule, 
the  bodies  of  the  Bombycine  Moths  are  large  and  thick, 
and  the  mouth  parts  are  generally  inconspicuous  or  absent 
altogether.  In  the  latter  case  the  adult  moth  is  unable  to 
take  any  food,  consequently  these  moths  are  seldom  to  be 
seen  visiting  flowers,  as  do  the  Hawk  Moths  and  the  Owlet 
Moths.  The  caterpillars  are  frequently  thickly  clothed 
with  hairs,  and  they  nearly  always  change  to  pupae  within 

the  protection  of 
silken  cocoons. 
The  families  of 
this  group  in- 
clude some  of  the 
insects  most  de- 
structive to  vege- 
tation. 

The  most  beau- 
tiful American 
insects  are  the 
larger  forms  of 
the  Bombycine 
Moths.  The 
wonderful  trans- 
lucent beauty  of 
the  Luna  Moth, 
the  handsome  col- 

LUNA  MOTH  :  Reduced 

oring  of  the  Ce- 

cropia  Moth,  and  the  glorious  browns  of  the  Polyphemus 
Moth  deservedly  attract  the  attention  of  every  one  that  sees 


THE  BUTTERFLIES  AND   MOTHS  103 

them.  The  curious  cocoons  of  the  Promethea  Moth  fas- 
tened so  securely  to  the  branches  of  many  trees  and  shrubs 
may  be  found  throughout  the  winter  over  a  large  part  of 
North  America,  and,  if  brought  indoors,  will  yield  a  har- 
vest of  attractive  moths  in  early  summer. 

The  familiar  Tent  Caterpillar,  the  nests  of  which  are  to 
be  found  in  so 
many  wild  cherry 
and  apple  trees 
during  May  and 
June,  is  also  a 
smaller  example 
of  one  of  these 
families  of  silk 
spinners.  These 
Tent  Caterpillars 
are  very  easily 
reared  indoors,  so 
that  it  is  easy  to 
watch  them  spin 
their  cocoons, 
change  to  pupae,  and  emerge  later  as  rather  small  brown 
moths. 

The  most  notorious  member  of  the  nearly  related  family 
of  Tussock  Moths  is  the  destructive  Gypsy  Moth,  which 
during  the  last  few  years  has  done  enormous  damage  in 
New  England,  and  millions  of  dollars  have  been  spent  in 
fighting  it.  This  Gypsy  Moth  is  a  native  of  Europe  and 
was  introduced  into  America  about  1869.  Since  then 
it  has  gradually  spread  from  the  Massachusetts  town  where 
it  first  escaped,  and  threatens  to  become  one  of  the  most 
widespread  and  destructive  of  insect  pests.  It  is  very 
desirable  that  people  everywhere  should  be  on  the  watch 


104 


FARM   FRIENDS  AND   FARM   FOES 


for  it,  so  that  on  its  first  appearance  in  a  new  locality  it 
may  be  promptly  exterminated. 

The  adult  Gypsy  Moths  appear  upon  the  wing  during 
the  latter  part  of  summer.  The  females  are  larger  than 
the  males,  having  a  wing  expanse  of  nearly  three  inches, 
and  are  of  a  whitish  color.  Their  bodies  are  very  large 
and  heavy,  so  that  the  moth  is  able  to  fly  only  to  a  very 
slight  extent.  The  male  moths  have  a  wing  expanse  of 
less  than  two  inches,  and  are  of  a  brownish-yellow  color. 
Their  bodies  are  slender,  and  the  moths  are  able  to  fly 
readily. 

Soon  after  emerging  from  the  cocoons,  the  female  moths 
deposit  their  eggs  in  characteristic  masses,  each  mass  com- 
monly containing  about  five  hundred  eggs.  They  are  very 
likely  to  be  deposited  in  such  hiding  places  as  hollow  trees 
or  logs,  or  among  the  stones  of  stone  walls.  These  eggs 
remain  unhatched  until  about  the  time  the  leaves  begin  to 


appear  the  following  spring.  Then  they  hatch  into  tiny 
caterpillars  that  feed  upon  the  leaves.  These  grow  rapidly, 
molting  several  times  as  the  weeks  go  by,  until  finally  they 
become  full-grown  hairy  caterpillars  that  change  to  pupae 
within  very  slight  silken  cocoons,  if,  indeed,  the  few  silken 


THE   BUTTERFLIES   AND   MOTHS  105 

threads  that  commonly  protect  them  may  be  called  cocoons 
at  all.  A  short  time  later  they  change  again  to  adult 
moths. 

The  special  danger  from  these  Gypsy  Moths  is  due  to  the 
fact  that  they  multiply  so  rapidly,  feed  so  ravenously,  and 
attack  practically  all  kinds  of  growing  plants,  including  even 
the  coniferous  evergreens.  They  are  as  yet  comparatively 
little  injured  by  birds  or  parasitic  enemies,  although  every 
effort  is  being  made  by  official  entomologists  to  introduce 
into  this  country  the  various  parasites  that  keep  the  species 
in  check  in  Europe. 

The  Fall  Web-worm  is  a  caterpillar  easily  found  during 
late  summer  and  early  autumn.  Its  unsightly  nests  occur 
upon  a  great  variety  of  fruit  and  shade  trees.  These  Web- 
worms  hatch  from  eggs  laid  in  clusters  upon  the  leaves  by 
a  whitish  moth.  The  tiny  caterpillars  begin  to  spin  a  pro- 
tective web  as  soon  as  hatched.  When  very  young  they 
are  yellowish,  marked  with  black,  and  have  a  few  hairs 
projecting  from  their  bodies.  They  spin  webs  over  the 
nearer  leaves  and  then  feed  upon  their  green  substance, 
eating  this  out  so  that  the  network  of  veins  is  left.  As  the 
days  go  by,  they  enlarge  the  web  to  cover  other  leaves, 
which  are  in  turn  attacked.  They  molt  about  once  a  week, 
remaining  always  beneath  the  protecting  web.  As  they 
become  full  grown,  the  caterpillars  eat  more  or  less  of  the 
veins  along  with  the  leaf  substance,  but  they  generally  avoid 
the  midribs. 

The  full-grown  Web-worm  caterpillars  are  a  little  more 
than  an  inch  long,  with  the  body  densely  clothed  with 
yellowish  hairs.  They  now  leave  the  trees  and  descend  to 
the  ground.  There  they  spin  slight  silken  cocoons  within 
which  they  change  to  the  chrysalis  state,  and  remain  until 
the  following  June,  when  they  emerge  as  moths  to  lay  eggs 


io6  FARM   FRIENDS  AND   FARM  FOES 

for  another  brood  of  Web-worms.  There  is  thus  but  a  single 
generation  in  a  season. 

One  of  the  most  destructive  moths  that  has  ever  ap- 
peared in  America  is  the  famous  Brown-tail  Moth,  which 
has  already  done  an  enormous  injury  in  New  England, 
and  which  threatens  to  become  widely  distributed  over  the 
country.  This  pest  seems  to  have  been  accidentally  intro- 
duced with  a  shipment  of  nursery  stock  from  Europe.  It 
is  especially  troublesome  not  only  because  the  caterpillars 
feed  upon  practically  all  kinds  of  deciduous  trees,  but  also 
because  their  bodies  are  covered  with  poisonous  hairs  that 
cause  great  suffering  when  they  get  upon  the  human  skin. 

The  Brown-tail  Moth  passes  the  winter  in  characteristic 
nests  composed  of  compact  masses  of  leaves  fastened  to- 
gether by  silken  webs.  Inside  each  of  these  nests,  there 
are  commonly  several  hundred  tiny  caterpillars.  When 
spring  comes,  these  little  caterpillars  leave  the  nests  when 
they  wish  to  feed,  crawling  along  the  twigs  until  they 
reach  foliage.  At  first  they  return  to  the  nests  at  night 
and  when  not  feeding,  but  as  they  grow  larger,  they  are 
likely  to  desert  them  altogether.  They  continue  to  feed 
and  grow  until  about  the  middle  of  June.  Each  caterpillar 
then  spins  around  itself  a  silken  cocoon,  which  is  attached 
to  some  convenient  shelter,  commonly  the  leaves  of  the 
food  tree.  Inside  these  cocoons,  the  caterpillars  change  to 
chrysalids,  and  three  or  four  weeks  later  again  change  to 
the  peculiar  whitish  moths,  with  a  tuft  of  brown  hairs  at 
the  end  of  the  body  of  the  females.  This  tuft  gives  the 
insect  its  common  name. 

These  moths  appear  in  June,  and  lay  eggs  in  clusters  of 
two  or  three  hundred  each  on  the  leaves,  generally  near 
the  ends  of  the  branches.  During  the  latter  part  of  the 
summer  these  eggs  hatch  into  small  caterpillars,  which 


THE  BUTTERFLIES  AND   MOTHS  107 

feed  upon  the  leaves,  forming  gradually  the  protective 
nest  that  remains  upon  the  trees  through  the  winter.  The 
caterpillars  remain  inside  the  webbed  leaves,  and  thus 
wait  until  the  following  spring. 

An  effective  remedy  for  this  insect  is  that  of  burning 
the  winter  nests.  In  localities  where  it  is  not  yet  found,  a 
constant  watch  should  be  kept  for  it,  and  any  suspicious- 
looking  nests  should  be  sent  to  the  State  Experiment 
Station  for  examination. 

OWLET  MOTHS 

Another  important  family  of  the  Lepidoptera  is  that  of 
the  Owlet  Moths,  or  the  Night-flying  Moths  (Noctuidae). 
These  are  comparatively  small  moths,  having  thick  bodies, 
slender  antennas,  rather  small  wings,  and  for  the  most 
part  inconspicuous  colors.  The  larvae  are  generally 
smooth-bodied  worms,  that  commonly  transform  into  pupae 
in  earthen  cells.  This  group  includes  a  large  number  of 
very  destructive  insects,  of  which  the  Army  Worm  and  the 
Cutworms  are  good  examples. 

For  more  than  a  hundred  years,  the  Army  Worm  has 
been  destructive  to  American  crops.  It  is  one  of  those 
insects  which  appear  at  irregular  intervals  in  enormous 
numbers,  and  then  suddenly  disappear  .for  many  years. 
Briefly  told,  the  story  of  the  life  of  the  individual  Army 
Worm  is  this  :  — 

On  some  summer  night  there  appears  flying  about  a 
meadow,  a  rather  large,  light-brown  moth.  She  finds  a 
cluster  of  grass  blades.  Into  the  folded  leaves  of  one  or 
more  of  these,  she  pushes  a  number  of  small,  whitish 
eggs,  grouping  them  in  rows  of  a  dozen  or  more.  A  week 
or  ten  days  later,  each  egg  hatches  into  a  minute  whitish 
worm,  that  nibbles  at  the  grass  blades  at  night,  and  during 


io8 


FARM  FRIENDS  AND  FARM  FOES 


MOTH 


ARMY-WORM 


the  day  hides  beneath  the  grass  from  the  rays  of 
the  sweltering  sun. 

This  larva  grows  rapidly  in  size.     At  the  end 
of  a  week  it  molts  or  casts  its  skin,  a  process  in 

which  the  old 
skin  splits  open 
along  the  back, 
and  the  worm 
crawls  outclothed 
in  a  new  skin  that 
has  developed  be- 
neath the  old  one. 
Again  it  feeds  as 
before,  its  vo- 
racity increasing 
with  its  size.  This 
molting  is  re- 
peated four  or  five 
times  during  the 
month  after  the 
eggs  hatch,  so 
that  by  the  end 
of  this  period,  the 
insect  is  one  and 
a  half  inches  long, 
and  has  the  brown 
markings  of  the  full-grown  Army  Worm. 

The  instinct  of  the  caterpillar  now  teaches  it  to  seek 
more  secure  shelter  for  the  helpless  stage,  upon  which 
it  is  about  to  enter.  It  burrows  into  the  soil  an  inch 
or  less  and  wriggles  about  in  the  earth  until  it  pro- 
duces a  hollow  cell.  In  this  it  casts  its  skin  again  and 
becomes  a  pupa  —  the  third  stage  of  its  existence.  When 


LARVA 


PUPA 


THE  BUTTERFLIES  AND  MOTHS       109 

the  caterpillars  are  very  abundant,  many  of  them  do  not 
go  into  the  ground,  but  change  to  pupae  beneath  whatever 
shelter  may  be  at  hand.  About  a  fortnight  later,  another 
change  takes  place,  and  the  fully  developed  moth  emerges 
from  the  pupa,  thus  completing  the  cycle  of  the  insect's 
life.  The  moths  fly  toward  dusk  and  at  night,  and  by 
means  of  their  long  tongues,  coiled  up  when  not  in  use, 
they  suck  the  nectar  of  various  flowers. 

During  ordinary  years  the  Army  Worm  is  present  in 
most  of  the  regions  where  its  outbreaks  occur,  individual 
caterpillars  feeding  in  meadows  and  pasture  lands,  but  the 
number  is  not  sufficient  to  attract  notice.  At  such  times, 
their  habits  of  life  are  very  similar  to  those  of  the  common 
Cutworm,  to  which,  indeed,  the  Army  Worm  is  closely  re- 
lated. It  is  only  when  the  caterpillars  become  so  nu- 
merous that  they  exhaust  the  food  supply  of  the  field  in 
which  they  develop,  that  the  "  army "  habit  is  assumed. 
Then,  however,  they  are  forced  to  seek  new  quarters  for 
food,  and  as  their  only  mode  of  progress  is  by  crawling 
along  the  ground,  they  move  in  solid  masses  toward  ad- 
jacent fields.  They  feed  preferably  upon  the  various 
grasses  and  grains,  although,  when  driven  by  hunger,  they 
will  eat  the  leaves  of  clover  and  other  plants. 

One  of  the  most  effective  means  of  preventing  the  in- 
juries of  these  armies  of  caterpillars  is  to  dig  a  deep  ditch 
or  trench,  into  which  the  worms  fall  in  great  numbers, 
where  they  can  be  destroyed  by  various  mechanical  devices. 

The  Cutworms  form  one  of  the  most  vexatious  groups 
of  injurious  insects.  They  are  the  smooth-skinned,  thick- 
bodied  worms,  an  inch  or  so  in  length,  which  are  so  often 
to  be  found  by  careful  digging  about  a  tomato  or  cabbage 
plant  that  has  been  cut  off  in  the  night.  They  attack  a 
great  variety  of  crops  and  often  cause  serious  losses. 


no  FARM  FRIENDS  AND   FARM  FOES 

The  Cutworms  are  the  young  or  larvae  of  rather  large 
millers,  or  night-flying  moths  of  the  family  Noctuidae.  One 
of  them  is  represented  natural  size  in  the  figure  below. 
In  the  case  of  several  of  our  common  species  —  for  there 
are  many  different  kinds  of  Cutworms 
—  these  moths  lay  eggs  in  grass  lands 
CUTWORM  LARVA  jate  jn  summer  or  early  in  autumn. 
The  eggs  soon  hatch  into  small  worms  that  feed  upon  the 
grass  until  cold  weather,  when  they  seek  such  shelter  as 
can  be  found  in  the  soil  or  rubbish  at  or  near  the  surface 
of  the  soil,  and  remain  quiet  until  spring.  They  are  likely 
to  be  half  grown  when  winter  closes  in. 

When  the  sunny  days  of  April  come,  the  Cutworms 
again  begin  to  feed.  If  the  grass  land  has  been  plowed, 
they  eat  such  green  things  as  they  can  find,  until  the  corn 
or  other  crop  comes  up ;  then  they  feed  upon  it.  If  they 
are  in  grass  near  gardens,  they  are  likely  to  wander  over 
the  garden  more  or  less,  taking  such  plants  as  they  find. 
They  travel  at  night,  remaining  concealed  in  or  near  the 
soil  during  the  day. 

Toward  the  latter  part  of  the  spring  the  Cutworms  be- 
come full  grown  in  this  larval  state.  They  then  burrow 
into  the  soil,  and  change  to  pupae  or  chrysalids  of  a 
brownish  color.  About  two  weeks  later  they  again  change 
to  adult  moths. 

Various  remedies  for  Cutworms  are  known.  In  gardens, 
when  a  plant  has  been  cut  off,  a  prompt  search  of  the  soil 
about  the  base  of  the  stem  will  generally  reveal  the  worm, 
which  may  then  be  killed.  On  a  larger  scale,  the  use  of  a 
poisoned  bait  made  by  mixing  a  small  amount  of  Paris 
green  with  bran  or  middlings,  or  a  mixture  of  the  two,  has 
been  successful.  This  is  scattered  upon  the  grass  beside 
the  field  to  be  protected,  or  is  placed  in  rows  in  the  field 


THE   BUTTERFLIES   AND   MOTHS 


in 


itself.  But  great  care  is  of  course  necessary  in  such  use 
of  poisons. 

It  is  not  often  that  an  insect  attacks  three  crops  which 
are  so  different  in  every  way  as  cotton,  corn,  and  tomatoes. 
This  is  the  case,  however,  with  the  noctuid  moth,  known 
by  the  various  names  of  Bollworm,  Corn  Worm,  and  To- 
mato Fruit  Worm.  The  cater- 
pillars have  a  general  resemblance 
to  some  of  the  commoner  cut- 
worms, although  they  vary  greatly 
in  color  and  markings.  In  the 
Southern  states,  these  caterpillars 
feed  to  a  destructive  extent  upon 
the  bolls  of  cotton,  on  account  of 
which  they  are  called  Bollworms. 
In  regions  farther  north,  these 
caterpillars  feed  inside  the  husks 
of  green  corn,  upon  the  tassels  and 
immature  kernels,  on  account  of 
which  they  are  commonly  called 
Corn  Worms  or  Tassel  Worms. 

In  some  regions  where  tomatoes  are  largely  grown,  these 
caterpillars  feed  upon  the  green  fruit,  often  boring  into  it 
in  a  very  destructive  manner ;  consequently,  they  have  re- 
ceived the  name  Tomato  Fruit  Worm.  In  the  South,  how- 
ever, the  insect  does  not  confine  its  attention  to  cotton,  for 
it  often  feeds  also  upon  green  corn  even  in  cotton-growing 
regions. 

As  a  Corn  Worm,  the  life  history  of  this  insect  may  be 
summarized  in  these  words :  The  adult  yellowish  or  yel- 
lowish-green moths  appear  in  the  cornfield  early  in  the 
summer  and  deposit  their  eggs  upon  the  leaves  or  stalks 
of  the  growing  plants.  Four  or  five  days  later  these  eggs 


COTTON  BOLLWORM 


H2  FARM  FRIENDS  AND   FARM   FOES 

hatch  into  small  caterpillars  that  commonly  hunt  until  they 
find  the  end  of  a  young  ear  of  corn,  where  they  feed  upon 
the  green  tassels  and  gradually  burrow  beneath  the  husks, 
eating  both  tassels  and  young  kernels  as  they  proceed. 
When  once  beneath  the  protection  of  the  outer  husks,  they 
remain  until  they  become  full  grown.  They  are  then  a 
little  over  an  inch  long.  Each  makes  a  round  hole  through 
the  husk  and  enters  the  soil  below  the  plant,  where  within 
an  oval  cell  it  changes  to  a  pupa.  Some  time  later  it 
again  changes  to  an  adult  moth. 

The  life  history  of  the  insect  when  it  feeds  upon  cotton 
is  very  similar,  except  that  the  young  cotton  bolls  are  at- 
tacked instead  of  the  ears  of  corn.  An  interesting  fact  in 
regard  to  the  species  is  that  in  the  more  northern  regions 
this  insect  does  not  seem  to  be  able  to  survive  the  winter 
in  any  stage.  Consequently,  it  is  believed  that  most  of 
the  injury  there  done  each  season  is  caused  by  moths  that 
fly  northward  from  the  south. 

The  Larger  Cornstalk-borer,  which  is  also  known  as  the 
Sugarcane-borer,  is  one  of  the  most  generally  destructive 
insects  in  the  Southern  states.  Early  in  spring,  about  the 
time  the  young  corn  plants  are  four  or  five  inches  high,  a 
rather  small  moth  appears  in  the  fields  and  lays  eggs  upon 
the  leaves  of  the  young  corn  plants.  These  eggs  soon  hatch 
into  small  caterpillars  that  burrow  into  the  stalk  until  they 
reach  the  pith.  Then  they  begin  feeding  upon  this  pith, 
usually  burrowing  upward.  They  continue  to  feed  and 
grow  for  several  weeks,  often  coming  out  of  the  original 
plant  and  burrowing  into  a  neighboring  one.  About  mid- 
summer, they  become  full  grown  in  the  larval  state.  Then 
they  change  to  pupae  inside  the  tunnels  within  the  corn- 
stalks, to  emerge  a  fortnight  later  as  adult  moths. 

These  moths  lay  eggs  for  a  second  generation  of  cater- 


THE   BUTTERFLIES   AND   MOTHS 


pillars,  that  burrow  into  the  cornstalks  in  the  same  way, 
and  usually  remain  through  the  winter  in  their  tunnels  with- 
out transforming  to  pupae.  Early  in  spring,  however,  this 
transformation  takes  place,  and  the  moths  appear  in  time 
to  lay  their  eggs  upon  the  young  corn  plants  of  a  new 
season. 

This  Cornstalk-borer  is  especially  destructive  in  regions 
where  old  cornstalks  are  left  in  the  field  through  the  winter. 
The  destruction  of  these,  with  the  hibernating  caterpillars 
inside,  will  very  largely  reduce  the  injury  the  following 
season.  It  is  another  one  of  the  numerous  insects  which 
point  the  moral  that  "  good  agriculture  is  the  first  and  best 
insecticide." 

CODLING  MOTH 

It  is  more  than  a  century  since  the  Codling  Moth  or 
Apple  Worm  began  to  prey  upon  the  fruit  of  American 
orchards.  This  pest  was 
introduced  from  Europe 
early  in  our  history.  Its 
life  history  in  brief  is 
this  :  - 

The  parent  insect  is 
a  small  chocolate-brown 
moth,  scarcely  half  an 
inch  long,  which  appears 
among  the  trees  in  spring 
about  the  time  the  young 
apples  are  forming.  The 
tiny  whitish  eggs  are  de- 
posited upon  the  fruit, 
stems,  or  leaves.  These  eggs  shortly  hatch  into  small  larvae 
that  commonly  enter  the  blossom  end  of  the  apple,  where 


CODLING 
MOTH 


FARM   FRIENDS   AND    FARM   FOES 


they  are  likely  to  nibble  for  a  few  days  before  they  burrow 
down  toward  the  core.  When  once  within  the  fruit,  they 
feed  and  grow  for  about  a  month.  Then  they  leave  the 
fruit  and  find  shelter  where  they  spin  their  cocoons,  within 
which  they  change  to  pupae.  Each  insect  remains  in  this 
pupal  state  for  about  two  weeks ;  then  it  emerges  as  an 

adult  moth,  like  the 
one  that  laid  the 
original  eggs. 

These  moths  com- 
monly lay  eggs  for 
a  second  brood  of 
worms,  that  de- 
velop in  the  apples 
throughout  the  late 
summer  or  early  au- 
tumn months.  The 
larvae  leave  the  ap- 
ples when  full  grown 
and,  in  the  shelter  of  rough  bark  or  something  similar,  spin 
silken  cocoons,  within  which  they  remain  until  about  the 
time  the  apples  blossom  the  following  spring.  Then  they 
change  to  pupae,  and  change  again  in  about  two  weeks  to 
adult  moths.  There  are  two  broods  of  these  moths  a  year, 
each  distributed  over  a  long  period. 

The  injuries  of  the  Codling  Moth  larvae  may  be  pre- 
vented to  a  large  degree  by  spraying  with  arsenical  poisons 
in  spring,  soon  after  the  petals  of  the  blossoms  have  fallen. 
It  is  especially  desirable  that  a  thorough  spraying  be  given 
before  the  calyx  end  of  the  young  apple  is  closed.  In  the 
picture  above,  the  calyx  in  each  of  the  outer  fruits  is  open ; 
that  of  the  larger,  middle  fruit  is  closed.  By  means  of  the 
spraying  machine,  the  fruit  grower  is  able  to  place  in  the 


APPLES  SHOWING  CALYX  OPEN  AND  CALYX 
CLOSED 


THE   BUTTERFLIES   AND   MOTHS  115 

upper  or  blossom  end  of  the  apple  a  few  particles  of  poison, 
so  that  when  the  newly  hatched  worm  nibbles  at  the  skin, 
it  is  likely  to  eat  one  or  more  of  these  particles  and  be  killed. 
Two  sprayings  are  generally  desirable ;  the  first  less  than  a 
week  after  the  petals  fall,  and  the  second  ten  days  or  two 
weeks  after  the  first. 

LEAF  ROLLERS  AND  LEAF  MINERS 

Examples  of  the  great  group  of  Leaf  Rollers,  several 
families  of  which  are  commonly  classed  together  into  one 
superfamily  (Tortricina),  are  easily  found  wherever  there 
are  trees  or  shrubs  in  variety.  These  insects  are  espe- 
cially characterized  by  the  ability  of  the 
larvae  to  fasten  together  the  edges  of 
leaves  by  means  of  silken  threads. 
Sometimes  it  will  be  a  single  leaf 

cleverly  rolled  into  a  tube,  and  at  other 

LEAF  ROLLER  MOTH 
times  it  will  be  a  number  of  leaves  upon 

the  same  branch,  sewed  together  to  make  a  tent.  In 
either  case,  the  leaves  thus  united  are  utilized  as  a  home 
for  the  young  caterpillars,  that  feed  upon  the  green  sub- 
stance on  the  inside,  and  so  escape,  to  a  large  extent,  the 
attacks  of  birds. 

When  fully  grown,  the  caterpillars  change  to  pupae, 
either  in  the  webbed  home  or  in  some  other  shelter,  and 
a  little  later  they  change  again  into  small  moths.  One  of 
the  commonest  examples  of  this  great  group  is  the  so- 
called  Rose  Leaf  Roller,  which  is  also  often  found  upon 
the  leaves  of  apple  and  many  other  trees.  Fortunately  in 
the  case  of  most  Leaf  Rollers,  the  protecting  web  does 
not  prevent  the  access  of  parasitic  flies  which  destroy  the 
caterpillars  in  great  numbers. 

The  smallest  of  the  scale-winged  insects  belong  to  the 


Ii6  FARM  FRIENDS  AND   FARM  FOES 

great  group  of  Leaf  Miners  (Tineina).  For  the  most 
part,  these  insects  in  their  larval  stages  live  between  the 
upper  and  lower  surfaces  of  leaves  as  true  miners.  Some 
of  them,  however,  have  other  habits.  A  comparatively 
small  number  make  tiny  silken  cases  which  serve  as  houses 
within  which  they  live.  Others  burrow  in  fruits,  stems, 
or  seeds.  Still  others  feed  upon  wool  or  furs  or  feathers ; 
the  common  clothes  moths  are  illustrations  of  these. 

If  you  will  look  carefully  at  the  leaves  of  the  nearest 
apple  tree,  you  will  be  likely  to  find  illustrations  of  the  true 
Leaf  Miners.  Several  distinct  species  live  upon  the  tissues 
of  apple  leaves.  One  of  the  commonest  is  the  Apple-leaf 
Trumpet  Miner,  which  is  easily  recognized  by  the  curious 
trumpet  shape  of  the  yellowish  mine  that  is  conspicuous 
within  the  green  tissues  of  the  leaf.  The  life  history  of 
this  species  is  very  simple.  A  small  brown  moth  lays  her 
egg  upon  the  surface  of  the  leaf.  The  egg  shortly  hatches 
into  a  tiny  larva,  that  burrows  through  the  skin  of  the  leaf 
and  feeds  upon  the  green  cells  inside.  Here  it  continues 
to  feed  and  grow  for  some  weeks,  casting  its  skin  occasion- 
ally. It  remains  as  a  larva  within  the  mines  when  the 
leaves  fall  in  autumn.  In  the  spring  it  changes  to  a  pupa, 
still  within  the  fallen  leaf,  and  a  little  later  the  moth 
emerges.  This  insect  is  sometimes  so  numerous  as  seri- 
ously to  injure  the  foliage  of  the  trees. 

PEACH-TWIG  BORER 

The  insect  which  in  California  is  known  as  the  Peach 
Worm  and  which  in  many  other  parts  of  the  country  is 
called  the  Peach-twig  Borer,  is  one  of  the  most  extraor- 
dinary of  fruit  insects.  This  is  due  to  the  remarkable  varia- 
tion of  the  habits  of  the  larvae  in  the  three  different  broods 
developed  during  each  year. 


THE   BUTTERFLIES   AND   MOTHS 


117 


PEACH-TWIG  BORER:  WINTER  BURROW 
CUT  OPEN 


The  life  history  of  this  pest  in  California  has  been  very 
carefully  worked  out  by  the  investigators  of  the  State  Ex- 
periment Station.  In  brief  it  is  as  follows :  Throughout 
the  fall  and  winter  the  small  caterpillars  are  hidden  within 
curious  cells  that  they  make  in  the  bark  of  the  trees,  es- 
pecially in  the  forks  of 
the  branches.  These  lit- 
tle burrows  are  furnished 
with  a  silken  lining,  and 
are  covered  with  a  sort 
of  thatch  made  by  fasten- 
ing tiny  bits  of  bark  to- 
gether with  silk.  Within 
these  hibernating  cells, 
the  insects  are  protected 
from  most  dangers.  Early 
in  spring,  the  larvae  become  active  and  get  ready  to  emerge 
from  their  winter  quarters  by  tearing  away  a  part  of  the 
protective  covering.  Finally  they  emerge  and  attack  the 
young  buds,  burrowing  their  way  into  the  pith  of  the  short 
branches.  They  thus  become  twig  borers,  and  often  do 
great  damage. 

After  a  few  weeks  of  this  existence,  they  hide  within  the 
bits  of  curled  bark  upon  the  trunk  and  larger  branches, 
where  they  change  to  pupae,  generally  very  slightly  shel- 
tered by  a  few  silken  hairs.  These  pupae  shortly  change 
again  into  adult  moths,  that  lay  their  eggs  on  the  bark  of 
the  young  twigs.  These  eggs  soon  hatch  into  tiny  larvae, 
which  also  become  twig  borers  during  the  first  weeks  of 
their  life,  usually  upon  a  tree  loaded  with  fruit.  This  brood 
of  worms  lives  as  twig  borers  for  only  about  three  weeks. 

They  then  leave  the  twigs  and  burrow  into  the  green 
peaches,  entering  at  the  stem  end  and  feeding  freely  upon 


n8  FARM  FRIENDS   AND   FARM  FOES 

the  green  pulp.  Here  they  continue  until  they  become 
full-grown  as  larvae,  often  doing  an  enormous  amount  of 
damage  to  the  peach  crop.  Finally  they  emerge  from  the 
fruits  and  change  to  pupae  on  the  outside  of  the  peach, 
generally  in  or  near  the  stem  cavity.  A  week  later,  these 
pupae  change  to  moths  that  deposit  their  eggs  upon  the 
peaches,  and  these  eggs  hatch  into  worms  that  also  burrow 
into  the  peach  fruits,  finally  maturing  and  pupating  on  the 
outside  of  the  fruits  in  the  same  way  that  the  second 
generation  did. 

A  week  later,  the  third  brood  of  moths  appears,  generally 
during  the  latter  part  of  August,  and  these  deposit  their 
eggs  upon  the  bark  of  the  trees.  The  larvae  that  hatch 
from  this  lot  of  eggs  burrow  immediately  into  the  bark 
and  hollow  out  the  hibernating  cells. 

There  is  thus  in  the  extraordinary  history  of  this  Peach- 
twig  Moth  a  series  of  three  broods  of  larvae,  one  of  which 
is  exclusively  a  borer  of  bark  and  twigs,  the  second  of 
which  is  both  a  twig  borer  and  a  fruit  worm,  and  the  third 
of  which,  on  fruiting  trees,  is  exclusively  a  fruit  worm.  It 
has  been  found  that  the  hibernating  worms  may  be  de- 
stroyed by  spraying  the  trees  in  spring  with  a  lime,  salt, 
and  sulphur  wash,  and  the  injuries  maybe  prevented  to  a 
considerable  extent  by  burying  or  covering  the  piles  of 
wormy  peaches. 


TINEID  /    \  MOTH 


THE   BUTTERFLIES   AND   MOTHS  119 

OBSERVATIONS   FOR   PUPILS 

BUTTERFLIES 

A 

1.  Make  a  list  of  butterflies  that  you  know  by  sight.     If  you  have 
access  to  the  Butterfly  Book  or  Comstock1s  How  to  know  the  Butterflies, 
you  can  identify  those  you  see. 

2.  Keep  the  caterpillars  of  some  butterflies  in  a  vivarium  to  see  their 
changes.      You  can  probably  find  some  one  of  these  :  the  Cabbage 
Worm,  Orange-dog,  Monarch  Butterfly  caterpillar  on  milkweed,  Black 
Swallow-tail  caterpillar  on   parsley,  celery,  or  parsnip   plants   or  the 
Mourning  Cloak  Butterfly  caterpillars  on  willow,  poplars,  and  elm. 

3.  Read  some  of  the  chapters  on  Butterflies  in  Dickerson's  Moths 
and  B:dterflies ;  also  such  of  the  following  as  you  have  access  to  :  — 

American  Insects,  pages  446-454.     Nature  Biographies,  pages  i-io,  11-21,  71-88. 
Stories  of  Insect  Life,  First  Series,  pages  12-17,  22-27,  37-40. 

B 

i.  Write  or  tell  the  story  of  The  Life  of  a  Butterfly.     Follow  some 
such  outline  as  this  :  — 

The  laying  of  the  egg. 

The  hatching  of  the  larva. 

The  growth  of  the  larva. 

The  change  to  the  chrysalis. 

The  change  to  the  butterfly. 

The  habits  of  the  butterfly. 
If  the  story  is  written,  illustrate  it  by  some  sketches  of  the  life  stages. 

SPHINX  MOTHS 

1.  Late  in  summer  or  early  in  autumn  one  can  generally  find  larvae 
of  Sphinx  Moths  by  a  little  searching  of  these  plants  :  Tomato,  grape, 
woodbine,  or  Virginia  creeper,  purslane,  and  various  trees  and  shrubs. 

2.  When  a  Sphinx  larva  is  found,  keep  it  in  a  vivarium  with  two 
inches  of  earth  in  the  bottom.     Feed  it  regularly  and  keep  the  vivarium 
clean.     When  it  is  full  grown,  it  will  probably  enter  the  soil  to  pupate. 
Then  put  the  vivarium  away  in  a  cool  cellar  till  spring. 

3.  Read  these  accounts  of  Sphinx  life  histories  :  — 

American   Insects,   pages    431-439.      Moths    and    Butterflies,   pages    224-242. 
Stories  of  Insect  Life,  Second  Series,  pages  38-45, 56-62. 


120  FARM  FRIENDS  AND   FARM  FOES 


BOMBYCINE  MOTHS 

1.  In  winter  or  early  spring  hunt  for  cocoons  of  the  giant  silkworms 
—  Cecropia,  Promethea,  Polyphemus,  and  other  large  moths.     When 
found,  keep  in   a  cool  place  until  April  or  May,  then  bring  into  the 
schoolroom  to  see  the  moths  emerge. 

Read  the  chapters  on  these  moths  in  Dickerson's  Moths  and  Butter- 
flies. 

2.  In  spring  you  can  easily  find  nests  of  the  Tent  Caterpillar.    Bring 
in  a  few  larvae  and  rear  in  a  vivarium. 

Read  Nature  Biographies,  pages  22-34. 

3.  In  autumn  you  can  generally  find  nests  of  the  Fall  Web-worm  and 
easily  rear  a  few  of  the  larvae. 

OTHER  INSECTS 

I.  If  you  do  not  find  Cutworms  in  your  garden,  you  can  probably 
find  them  under  boards  along  fences  or  roadsides.  Keep  a  few  in  a 
vivarium,  feeding  them  leaves  of  clover,  and  see  if  you  can  rear  them 
successfully. 

2.  If  the  Bollworm,  Corn  Worm,  or  Tomato  Fruit  Worm  occur  in 
your  region,  see  if  you  can  find  and  rear  some  of  the  larvae. 

3.  Late  in  autumn  get  some  nearly  full-grown  Codling  Moth  larvae  in 
apples,  place  in  a  vivarium,  and  see  if  you  can  get  them  to  spin  cocoons. 
Keep  these  to  see  if  you  can  get  the  moths  from  them. 

4.  Make  an  estimate   of  the  percentage   of  apples   injured  by  the 
Codling  Moth  in  some  orchard.      Is  the  injury  less  in  orchards  sprayed 
in  spring  than  in  those  not  sprayed  ? 

5.  A  little  searching  of  the  leaves  of  trees  and  shrubs  at  almost  any 
time   in   summer  will  reveal  examples  of  leaf  rollers  at  work.     One 
species  is  common  in  the  leaves  of  cultivated  strawberries.    Another 
conspicuous  one  is  the  Wild  Cherry  Tent-maker.     Rear  some  of  the 
larvae  into  moths.     A  few  small  caterpillars  can  be  easily  reared  in  a 
covered  jelly  glass  or  a  glass  fruit-jar. 

6.  Examine  the  leaves  of  apple  and  other  trees  for  leaf  miners.    They 
are  generally  abundant  in  summer  and  early  autumn.     Break  off  a  twig 
with  infested  leaves  and  put  it  in  a  bottle  of  water  to  keep  the  larvae  alive 
until  they  change  to  pupae.     Then  put  the  leaf  in  a  jelly  glass  or  other 
suitable  receptacle,  covering  with  cheesecloth  held  in  place  by  a  rubber 
band. 


THE   BUTTERFLIES   AND   MOTHS  121 

7.  Examine  peach  trees  and  peach  fruits  for  the  Peach-twig  Moths. 
See  if  you  can  rear  the  moths. 

Read  such  of  these  references  as  your  teacher  may  request :  — 

The  Brown-tail  Moth  and  How  to  Control  It,  Farmers'  Bulletin  264.  The 
Gypsy  Moth  and  How  to  Control  it,  Farmers'  Bulletin  275.  The  Cotton  Bollworm, 
Farmers'  Bulletin  290.  Insects  Affecting  the  Cotton  Plant,  Farmers'  Bulletin  47. 
The  Imported  Cabbage  Worm,  U.  S.  Bureau  of  Entomology,  Circular  60.  The 
Peach-tree  Borer,  U.  S.  Bureau  of  Entomology,  Circular  54. 


WINTER  NEST  OF  BROWN-TAIL  MOTH 


CHAPTER  IX 


The  Two-winged  Flies 

So  far  as  numbers  of  individuals  are  concerned,  the 
Two-winged  Flies  of  the  order  Diptera  are  among  the  most 

abundant  of  all 
insects.  These 
are  distinguished 
by  the  fact  that 
there  is  but  one 
pair  of  wings,  al- 
though in  most 
species  there  is 
a  pair  of  curious 
little  projections 
called  halteres 
or  "balancers" 
which  represent 
the  second  pair 
of  wings.  The 
flies  have  com- 
plete transformations,  and  in  the  larval  state  commonly  ex- 
ist as  footless  maggots.  The  mouth  parts  are  formed  for 
sucking,  although  there  are  often  special  modifications  for 
biting,  in  connection  with  the  sucking  apparatus. 

Fortunately,  there  are  comparatively  few  species  of  Dip- 
tera that  are  destructive  to  cultivated  crops.  Among  these 
few,  however,  are  some  of  the  most  troublesome  of  all  in- 
jurious insects,  such  as  the  Hessian  Fly,  the  Apple  Maggot, 


THE  TWO-WINGED   FLIES  123 

the    Pear    Midge,    the  Clover-seed    Midge   and    certain 
other  pests. 

GALL  GNATS 

The  Hessian  Fly  belongs  to  the  family  of  Gall  Gnats 
(Cecidomyiidae).  These  are  mosquito-like  flies  which  live 
in  the  larval  state  upon  the  growing  tissues  of  plants, 
commonly  causing  an  abnormal  swelling,  which  is  called  a 
gall.  In  the  case  of  the  Hessian  Fly,  the  adult  insect  is  a 
small  creature  with  smoky  brown  wings,  which  appears  in 
the  wheat  fields  in  autumn  soon  after 
the  young  plants  are  up.  It  deposits 
eggs  upon  the  leaves,  generally  a  little 
above  the  joints.  These  eggs  shortly 
hatch  into  very  small  maggots  that 
work  their  way  down  to  the  joints  and 
into  the  space  between  the  sheath  and 
the  main  stalk.  Here  they  remain 
and  gradually  absorb  the  sap  of  the 
plant.  They  grow  rather  slowly,  and  HESSIAN  FLY 

their  presence  causes  a  slight  swelling  Magnified 

of  the  surrounding  tissues  and  prevents 
the  normal  growth  of  the  young  wheat  plant.  After  some 
weeks,  they  become  full  grown  in  this  larval  stage,  and  now 
change  to  what  is  called  the  flaxseed  condition.  To  bring 
about  this  change  the  outer  skin  of  the  larva  separates  from 
the  skin  beneath  and  gradually  hardens  into  a  brown  pro- 
tective covering.  This  covering,  which  looks  like  a  flax- 
seed,  is  commonly  said  to  be  the  puparium.  It  corresponds 
in  a  way  to  the  cocoon  of  a  moth  in  that  it  serves  as  a  pro- 
tection to  the  insect  inside,  although  its  method  of  formation 
is  entirely  distinct  from  that  by  which  a  cocoon  is  formed. 

The   larvae   remain   within   these    flaxseeds  throughout 


124  FARM  FRIENDS  AND   FARM  FOES 

the  winter.  In  the  spring,  still  inside,  they  change  to  pu- 
pae, and  a  little  later  change  again  to  adult  Hessian  Flies. 
These  adults  lay  eggs  for  another  generation  of  larvae  that 
attack  the  wheat  in  the  spring  and  cause  much  of  it  to  be 
so  dwarfed  and  weakened  that  the  crop  is  seriously  injured. 
As  a  rule,  this  brood  of  flies  seems  not  to  become  mature 
until  the  latter  part  of  the  season. 

In  the  case  of  an  insect  so  minute  and  so  protected 
during  its  earlier  stages  as  the  Hessian  Fly,  many  insecti- 
cidal  methods  of  controlling  it  are  useless.  Consequently, 
farmers  must  resort  to  agricultural  methods  if  they  would 
prevent  damage  by  it.  One  of  the  most  successful  of 
these  methods  is  that  of  planting  narrow  strips  of  wheat 
early  in  the  fall,  to  attract  the  flies  to  lay  their  eggs,  in 
order  that  the  main  crop  of  wheat  planted  later  may  escape 
infestation.  The  early  trap  crop  may  then  be  plowed  un- 
der, so  that  the  eggs  and  larvae  present  will  be  destroyed. 

Another  insect  belonging  to  this  same  family  and  also 
attacking  the  wheat  is  called  the  Wheat  Midge.  The 
larvae  in  this  case  are  found  in  the  heads  of  grain  rather 
than  in  the  stalks,  and  the  damage  they  do  is  in  the  de- 
struction or  dwarfing  of  the  kernels  of  wheat.  In  recent 
years  this  insect  seems  to  have  done  comparatively  little 
damage. 

Closely  related,  both  in  structure  and  habits,  to  the 
Wheat  Midge  is  a  tiny  fly  called  the  Clover-seed  Midge. 
The  flies  lay  their  eggs  in  the  blossom  heads  of  clover, 
and  the  eggs  hatch  into  larvae  that  develop  at  the  expense 
of  the  young  seeds,  often  causing  a  serious  lessening  of 
the  crop  where  clover  is  grown  for  seed.  The  injury  to 
hay  crops,  however,  is  very  slight. 

The  Pear  Midge  is  the  most  destructive  insect  of  this 
family  that  attacks  fruit.  The  eggs  are  laid  in  the  flower 


THE  TWO-WINGED   FLIES 


APPLE 
MAGGOT 

MAGNIFIED 


buds  and  hatch  into  larvae  that  attack  the  seed  cavities  of 
the  young  pears,  sometimes  doing  serious  damage.  When 
fully  developed  in  the  larval  state,  they  drop  to  the  ground 
where  they  change  to  pupae,  and  emerge  soon  after  as 
adult  flies.  Plowing  during  the  latter  part  of  June  and  fer- 
tilizing with  a  heavy  dressing  of 
some  potash  fertilizer  is  helpful  in 
destroying  the  larvae  and  pupae. 

CRANE  FLIES 

The  Crane  Flies  (Tipulidae)  are 
among  the  largest  of  the  Two-winged 
Flies.  These  insects  look  like  gi- 
gantic mosquitoes  and  may  be  seen 
throughout  the  summer  in  pastures 
and  meadows, as wellasabout houses. 
In  their  larval  stages  some  of  the 
commoner  Crane  Flies  feed  upon 

decaying  vegetation  and  occasionally  upon  grass  roots, 
although  they  are  very  seldom  destructive  in  America. 
These  flies  show  very  well  the  peculiar  balancers  that  rep- 
resent the  second  pair  of  wings. 

FRUIT  MAGGOTS 

Comparatively  few  Two-winged  Flies  are  injurious  to 
fruit  crops.  One  of  the  most  destructive  of  these  is  the 
Apple  Maggot  or  Railroad  Worm,  a  pest  that  is  often  very 
troublesome  in  orchards.  The  adult  fly  deposits  eggs  be- 
neath the  skins  of  young  apples  during  the  summer.  Each 
of  these  eggs  soon  hatches  into  a  small  footless  maggot 
that  tunnels  through  the  fruit  in  all  directions.  It  continues 
the  work  for  five  or  six  weeks,  by  which  time  the  apple  is 
pretty  well  "  railroaded  "  and  ruined  for  cooking  or  eating 


UARVA 


126  FARM  FRIENDS  AND   FARM  FOES 

.purposes.  The  injured  fruit  is  likely  to  fall  to  the  ground. 
Then  the  maggot  leaves  it  and  finds  shelter  in  the  soil  or 
in  the  rubbish  at  its  surface.  Here  it  changes  to  a  pupa, 
and  remains  until  the  following  sea- 
son when  it  emerges  as  an  adult  fly. 
Thus  there  is  but  one  brood  each 
year. 

Unfortunately  the  injuries  of  this 
insect  cannot  be  prevented  by  spray- 
ing.    The  eggs  are  deposited  beneath 
the  skin  of  the  fruit  out  of  the  reach 
CHANNELS  OF  of  insecticides.     The  best  method  of 

APPUE  MAGGOT  checking  its  increase  is  that  of  picking 

up  or  feeding  to  stock,  the  fallen  apples,  so  that  the  worms 
will  be  destroyed  before  they  go  into  the  ground.  This  is 
another  insect  that  indicates  the  necessity  of  cooperation 
in  agricultural  methods. 

A  closely  related  insect,  which  has  done  a  great  deal  of 
damage  in  Mexico,  is  the  Orange  Maggot  or  Orange  Fruit 
Fly.  This  attacks  oranges  in  very  much  the  same  way  that 
the  Apple  Maggot  attacks  apples.  When  introduced  into 
an  orange-growing  locality,  it  is  likely  to  become  a  serious 
pest.  The  fact  that  there  was  constant  danger  of  its  intro- 
duction into  the  orange-growing  regions  of  California  has 
caused  much  discussion  among  horticulturists.  It  is  one  of 
those  pests  for  which  fruit  growers  should  be  constantly  on 
the  watch,  although,  of  course,  there  is  no  danger  of  dam- 
age from  it  in  regions  where  the  citrous  fruits  are  not 
grown. 

ROOT  MAGGOTS 

There  are  a  number  of  destructive  species  of  flies  be- 
longing to  the  Root-maggot  group  (Anthomyiinae).  In 


THE  TWO-WINGED   FLIES  127 

the  adult  state,  these  flies  bear  a  general  resemblance  to 
the  familiar  house  fly,  although  commonly  they  are  some- 
what smaller  and  are  easily  distinguished  by  experts.  The 
Cabbage  Maggot,  which  is  also  known  as  the  Radish  Maggot, 
and  the  Turnip  Maggot,  is  a  good  example  of  these  insects. 
The  adult  flies  appear  in  the  cabbage  fields  when  the  plants 
are  set  out,  and  deposit  their 
small  white  eggs  about  the 
base  of  the  stalks.  A  few 
days  later  these  eggs  hatch 
into  tiny,  whitish,  footless 
maggots  that  attack  with 
their  rasping  mouth  parts  the 

outer   tissues  of  the  roots.  ^§$1  CABBAGE 

They  continue  to  feed  and  *J|^  MAGGOT 

grow  for  three  or  four  weeks, 
commonly  causing  the  death 
of  the  plant  on  account  of 
the  destruction  of  the  sec- 
ondary roots  or  of  the  girdling  of  the  primary  root.  By 
the  end  of  this  period  they  become  full-grown  as  larvae 
and  change  to  pupae. 

This  process  of  changing  to  the  pupa  state  in  a  large 
proportion  of  the  two-winged  flies  differs  from  that  of  most 
other  insects.  The  insects  are  unable  to  spin  cocoons,  but 
they  get  the  protection  of  an  outward  covering  in  this  way  : 
The  skin,  which  in  most  insects  is  cast  off  when  the  larva 
changes  to  a  pupa,  in  these  maggots  gradually  hardens  and 
becomes  brownish  in  color.  It  does  not  split  open  any- 
where, so  that  it  forms  a  covering  to  the  insect,  inside  which 
the  latter  becomes  a  pupa  after  this  outer  skin,  which  is 
now  called  the  puparium,  has  hardened.  It  remains  within 
this  puparium  about  a  fortnight  when  it  again  changes  into 


128  FARM   FRIENDS   AND   FARM   FOES 

an  adult  fly  that  breaks  through  the  outer  shell  and  emerges 
to  the  sunlight.  The  formation  of  the  puparium  takes 
place  in  the  soil  an  inch  or  less  below  the  surface. 

As  the  common  names  already  mentioned  indicate,  this 
little  pest  is  by  no  means  confined  to  cabbage ;  it  attacks 
radishes  and  turnips,  as  well  as  a  variety  of  wild  plants  be- 
longing to  the  mustard  family.  There  are  several  broods 
each  year.  The  insects  commonly  pass  the  winter  as 
adult  flies,  although  a  certain  proportion  of  them  hiber- 
nate also  in  the  puparia. 

The  Cabbage  Maggot  has  been  one  of  the  most  trouble- 
some insects  that  the  gardener  has  to  fight.  It  is  often 
very  destructive  in  seed  beds  where  the  young  cabbages 
for  late  planting  are  being  grown.  Recent  experiments 
have  shown  that  the  best  way  of  preventing  this  injury  is 
to  surround  the  seed  beds  with  a  broad  frame  twelve  inches 
high,  tacking  cheesecloth  over  the  frame.  If  the  frame  is 
so  tight  that  no  flies  can  enter,  the  seedlings  will  grow 
rapidly  and  be  free  from  injury  not  only  by  these  maggots, 
but  also  by  the  flea  beetles  which  are  often  very  destructive 
to  such  seedlings.  When  the  plants  are  large  enough  to 
set  out,  the  cloth  should  be  removed  and  full  exposure  to 
the  sun  be  given  for  at  least  a  week.  This  is  to  harden 
the  seedlings  so  that  they  may  be  transplanted  successfully. 

The  Onion  Maggot  is  another  vexatious  insect  belong- 
ing to  this  family,  which  is  very  similar  to  the  Cabbage 
Maggot  in  its  appearance,  habits,  and  life  history.  It 
attacks  onions,  especially  the  young  plants,  and  in  many 
regions  is  the  most  destructive  enemy  of  this  crop. 

Another  group  of  insects  belonging  to  this  same  family 
attacks  the  leaves  of  cultivated  crops  instead  of  the  roots. 
The  adult  flies  deposit  their  whitish  eggs  upon  the  surface 
of  the  leaves  of  beets,  spinach,  and  other  succulent  plants. 


THE  TWO-WINGED   FLIES  129 

These  eggs  very  soon  hatch  into  small  maggots  that  bur- 
row through  the  outer  skin  of  the  leaf  and  begin  to  de- 
velop as  miners  of  the  interior  tissue.  They  thus  become 
true  leaf  miners,  and  their  presence  is  soon  shown  by  the 
difference  in  the  color  of  the  surface  of  the  leaf.  By 
holding  such  a  leaf  up  to  the  light,  the  maggot  inside  can 
generally  be  seen.  These  larvae  continue  to  develop 
within  the  leaf  for  a  few  weeks  before  they  become  full 
grown,  and  by  this  time  a  single  larva  will  have  injured 
a  large  portion  of  a  leaf.  When  full  grown  they  burrow 
through  the  outer  skin  and  drop  to  the  ground,  where  they 
change  to  pupae  slightly  below  the  surface.  A  little  later 
they  again  change  to  adult  flies.  There  appear  to  be  sev- 
eral broods  each  year. 

As  is  the  case  with  the  root  maggots,  these  leaf-mining 
species  are  by  no  means  confined  to  cultivated  crops.  They 
may  very  commonly  be  found  at  work  upon  wild  plants,  such 
as  the  white  pigweed  or  some  of  the  commoner  docks. 

OBSERVATIONS   FOR   PUPILS 
HESSIAN  FLY 

1.  If  you  live  in  a  wheat-growing  region,  learn  what  you  can  about 
local  damage  by  the  Hessian  Fly.     If  not  now  injurious,  ask  your  farmer 
friends  if  it  has  been  in  the  past. 

2.  Examine  wheat  fields  to  see  if  you  find  injured  plants.     If  so,  look 
for  the  larvae  or  "  flaxseeds  "  of  this  insect. 

3.  If  found,  place  the  flaxseeds  in  a  glass  dish  to  see  if  you  can  rear 
the  flies. 

4.  Read  the  account  of  the  Hessian  Fly  in  Circular  70,  Bureau  of 
Entomology,  U.  S.  Department  of  Agriculture. 

APPLE  MAGGOT 

I.  If  you  live  in  an  apple  region,  determine  whether  this  insect  is  pres- 
ent. Examine  windfalls  of  early  varieties  to  see  if  the  characteristic  bur- 
rows in  the  pulp  are  present. 


130  FARM   FRIENDS  AND   FARM  FOES 

2.  If  the  pest  is  at  work,  gather  some  injured  apples,  and  place  in  a 
box  with  an  inch  or  two  of  soil  in  the  bottom.  The  larvae  will  probably 
enter  the  soil,  and  you  will  be  able  to  rear  the  flies. 

ROOT  MAGGOTS 

1 .  What  crops  in  your  region  are  injured  by  root  maggots  ? 

2.  Get  some  of  the  maggots  from  roots  of  radish,  turnip,  cabbage,  or 
onion.     Keep  in  moist  earth  and  see  the  change  to  puparia  and  later  to 
flies. 

3.  Try  to  find  eggs,  larvae,  and  puparia  about  the  roots  of  injured 
plants. 

LEAF-MINING  MAGGOTS 

1 .  Examine  the  leaves  of  beets,  spinach,  dock,  and  pigweed  to  find 
discolored  areas.     If  made  by  the  leaf  miners,  the  larvae  may  readily  be 
seen  by  holding  the  leaf  up  to  the  light  or  by  opening  the  mine. 

2.  Place  some  of  the  leaves  that  have  larvae  of  good  size  in  a  bottle 
of  water.     Set  in  a  vivarium  with  earth  in  the  bottom.     The  larvae  will 
probably  pupate  in  the  earth  and  later  change  to  flies. 

THE  STORY 

Tell  or  write  the  life  story  of  one  of  these  injurious  flies  that  you  know 
most  about.  Illustrate  by  drawings  on  blackboard  or  paper.  Perhaps 
this  outline  will  help  you :  — 

Size,  color,  and  appearance  of  the  fly. 

When  and  where  the  flies  are  found. 

When  and  where  the  eggs  are  laid. 

Size  and  color  of  the  eggs. 

How  soon  the  eggs  hatch. 

What  the  larvae  feed  on. 

How  long  the  larvae  live. 

Where  the  larvae  change  to  pupae. 

How  long  before  the  pupae  change  to  flies. 


CHAPTER   X 


The  Beetles  :  Order  Coleoptera 

THE  great  order  of  sheath-winged  insects  to  which  the 
beetles  belong  is  one  of  the  largest  and  most  important 
groups  of  insects. 
Most  of  its  mem- 
bers have  har- 
dened wing  cov- 
ers over  the  true 
wings,  and  the 
whole  outer  sur- 
face of  the  body 
is  hardened  in 
a  characteristic 
manner.  The 
larvae  are  grubs 
that  vary  greatly 
in  form  and  hab- 
its, and  the  pupa 
is  a  quiet  stage  in 
which  the  insect  does  not  eat  or  move  about. 

The  feeding  habits  of  the  adult  beetles  are  exceedingly 
varied ;  many  feed  upon  plant  tissues ;  many  others  upon 
animals,  alive  or  dead.  Among  the  plant-feeding  groups 
are  some  of  the  most  troublesome,  injurious  -insects,  while 
among  the  animal-feeding  forms  are  some  very  beneficial 
insects. 


LARVa 


Pupa 

WHITE  GRUB 

or 
MAY  BEETLE 

Eqq 

0 


Adult 


132 


FARM   FRIENDS   AND   FARM   FOES 


LAMELLICORN 
BEETLE 


LAMELLICORN  BEETLES 

Only  a  few  of  the  great  number  of  beetle  families  can 

be  considered  in  these  pages.     One  of  the  most  important 

of  these  is  the  great  group  of  Lamellicorn  Beetles  (Scara- 

baeids).  These  have  curious  enlargements  on  the  ends  of 
the  feelers  or  antennae,  each  swollen  part 
consisting  of  a  number  of  thin  plates  rest- 
ing upon  one  another.  The  May  Beetle  is 
a  typical  example  of  this  group. 

In  both  its  adult  and  its  larval  condition, 
the  May  Beetle  or  June  Bug  is  only  too 
familiar  to  most  people.  From  the  advent 
of  the  first  warm  days  in  spring  until  sum- 
mer is  well  along,  the  brown  beetles  are 
likely  to  be  seen  flying  about  trees  or  lights 

or  crawling  along  the  surface  of  the  ground.     These  beetles 

feed  freely  upon  the  leaves  of  a  great  variety    of  fruit 

and  shade  trees,  sometimes  doing  much  injury  in  this  way. 

They  deposit  their  eggs  about  the   bases  of  grass  stems, 

And  the  eggs  soon  hatch 

into  small  larvae  that  feed 

upon  the  roots  of  grasses 

and     gradually     develop 

into  the  well-known  white 

grubs,  which  are  almost 

always    to    be    found   in 

abundance    when    grass 

lands  are  plowed.     It  is 

believed  that  these  white 

grubs    require    at    least 

three  years  to  complete  their  development,  becoming  large 

toward  the  end  of  this  period  and  able  to  destroy  the  roots 


POTATO  INJURED  BY  WHITE  GRUB 
Reduced 


THE  BEETLES:  ORDER  COLEOPTERA     133 

of  many  plants.  They  finally  change  to  pupae  in  earthen 
cells  and  generally  change  again  to  adult  beetles  in  late 
summer  or  autumn.  The  beetles  remain  in  the  soil  until 
the  following  spring. 

The  white  grubs  have  many  enemies  among  birds  and 
wild  animals,  such  as  foxes  and  skunks.  These  natural 
enemies  are  the  most  potent  means  of  keeping  them  in 
check  in  regions  where  the  grubs  become  destructive. 
The  killing  of  the  adult  beetles  by  attracting  to  lights  or 
collecting  in  other  ways  will  often  become  necessary. 
This  is  a  case,  however,  where  concerted  action  by  all  the 
farmers  of  the  community  is  exceedingly  desirable. 

Another  vexatious  member  of  this  great  family  of  bee- 
tles is  the  so-called  Rose  Chafer  or  Rose  Bug.  This  is 
one  of  the  most  destructive  enemies  of  fruits.  The 
brown  beetles  appear  in  vast  swarms  early  in  sum- 
mer, when  the  wild  roses  are  in  blossom.  They 
feed  upon  the  leaves  and  flowers  of  a  great  vari- 
ety of  fruit  and  ornamental  plants,  such  as  apples,  ROSE 
pears,  plums,  peaches,  roses,  raspberries,  straw- 
berries, blackberries,  and  grapes.  They  often  do  serious 
damage  to  the  grape  crop  by  eating  the  blossoms.  The 
beetles  remain  active  two  or  three  weeks.  During  the 
latter  part  of  this  period,  the  eggs  for  a  new  brood  are 
laid  in  the  ground.  The  insect  chooses  for  this  purpose 
open  fields  and  meadows  having  a  sandy  soil.  About  a 
fortnight  later,  the  eggs  hatch  into  small  grubs  that  feed 
upon  roots  of  grasses.  These  grubs  become  full  grown,  or 
nearly  so,  during  the  summer  and  early  autumn.  On  the 
approach  of  winter,  they  burrow  deeper,  and  the  following 
spring  again  work  their  way  upward  near  the  surface. 
Here  in  earthen  cells  they  change  to  pupae,  and  emerge  a 
month  later  as  fully  developed  beetles. 


I34  FARM  FRIENDS  AND   FARM  FOES 

This  is  a  difficult  pest  to  contend  against  The  most 
effective  method  as  yet  employed  is  the  laborious  one  of 
picking  the  beetles  by  hand  and  destroying  them. 

CLICK  BEETLES 

Every  farmer's  boy  is  familiar  with  the  slender,  yellow 
Wireworms  so   commonly   found   when    grass   lands    are 
plowed.     These  insects  feed  upon  the  roots  of  grasses  and 
grains.     They  often  become  seriously  destructive  to  crops 
planted  upon  ground  that  has  been  in 
sod  for  several  years.     When  fully  de- 
veloped in  their  larval  stage,  these  Wire- 
worms  change  to  pupae  within  oval  cells 
in  the  soil  and  a  few  weeks  later  change 
again  into  adult  Click  Beetles  or  Elaters. 
They  usually   remain,  however,  within 
the  cells  until  the  following  spring,  the 
tissues  gradually  hardening  until  they 
become  very  firm  and  hard  even  for  a 
beetle.     Then  the  adults  come  forth  and 
EYED  ELATER  fly  freely   about>   often   visiting  various 

flowers  from  which  they  lap  up  the  nectar.  These  Elaters 
are  often  called  Snapping  Beetles  from  the  fact  that  when 
placed  upon  their  backs,  they  snap  upward,  apparently  in 
an  effort  to  regain  the.  crawling  position.  It  is  supposed 
that  the  eggs  are  laid  about  the  roots  of  grasses. 

The  Wireworms  are  very  difficult  to  destroy  by  any  form 
of  insecticides.  The  most  desirable  method  of  checking 
their  increase  seems  to  be  that  of  fall  plowing,  which  breaks 
up  the  pupal  cells  and  exposes  the  beetles  to  destruction 
by  weather  conditions  through  the  winter. 


THE  BEETLES:  ORDER  COLEOPTERA 


135 


LEAF  BEETLES 

One  of  the  most  generally  destructive  families  of  beetles 
is  that  of  the  Leaf  Beetles  (Chrysomelidae).  As  a  rule,  these 
are  elongated  or  roundish  beetles,  having  jaws  especially 
adapted  for  feeding  upon  leaves.  Their  larvae,  for  the 
most  part,  are  short,  thick  grubs,  with  well-de- 
veloped thoracic  legs.  They  feed  in  both  the 
larval  and  adult  states  upon  a  great  variety  of 
wild  and  cultivated  plants,  and  often  become  seri- 
ously destructive  to  the  latter. 

No  member  of  this  great  family  is  so  generally 
and  unfavorably  known  as  the  Colorado  Potato  Beetle. 
Originally  a  native  of  the  Rocky  Mountain  region,  where  it 
fed  upon  a  wild  species  of  Solanum,  —  the  genus  to  which 
the  common  potato  belongs,  —  it  started  eastward  as  soon 
as  the  settlers'  garden  patches  connected  its  home  with  the 
Atlantic  states  by  means  of  a  practically  continuous  potato 
field.  Then  it  boarded  transatlantic  steamships  and  stole 

a  passage  to  Europe, 
where  it  gained  a  de- 
cided foothold  before  re- 
ceiving the  attention  it 
deserved. 

The  various  stages 
of  the  Colorado  Potato 
Beetle  are  shown  in 
the  accompanying  pic- 
tures. The  brown-striped 
beetles  deposit  the  or- 
ange-colored eggs  in  masses  upon  the  leaves.  These  eggs 
shortly  hatch  into  the  curious  brown  grublike  larvae,  which 
feed  upon  the  tissues  of  the  leaves  and  cast  their  skins 


Pupa 


Adult 


COLORADO  POTATO-BEETLE 


136  FARM   FRIENDS  AND  FARM  FOES 

occasionally  as  they  increase  in  size.  In  three  or  four 
weeks,  they  become  full-grown  as  larvae.  Then  they  make 
their  way  into  the  soil  and  change  to  pupae.  Ten  days 
later  they  change  again  to  adult  beetles.  The  number  of 
broods  varies  with  the  latitude,  there  being  from  two  to 
four  each  year.  The  eggs  are  eaten  by  lady-bird  beetles, 
and  the  adults  are  devoured  by  certain  birds,  notably  the 
grosbeaks  and  the  bobwhite.  Both  larvae  and  adults  are 
readily  killed  by  spraying  or  dusting  the  potato  vines  with 
arsenical  poisons. 

Another  leaf  beetle  that  is  very  often  destructive  is  the 
Asparagus  Beetle.  This  is  one  of  those  numerous  pests 
that  have  been  introduced  into  America  from  Europe.  It 
is  not  yet  generally  distributed,  but  is  constantly  being  in- 
troduced into  new  localities  where  asparagus  is  grown. 
The  adult  beetle  is  rather  slender,  less  than  half  an  inch 
long,  and  is  easily  recognized  by  the  brilliant  combination 
of  black  marked  with  red  or  yellow.  When  such  a  beetle 
is  found  feeding  upon  asparagus,  it  is  pretty  certain  to  be 
this  Asparagus  Beetle.  If  there  are  twelve  spots,  however, 
it  is  probably  the  less  common  Twelve-spotted  Aspar- 
agus Beetle,  which  has  also  been  lately  introduced  from 
Europe. 

The  eggs  of  the  common  Asparagus  Beetle  are  deposited 
upon  the  leaves  and  stems  of  the  plants,  and  soon  hatch 
into  small  grublike  larvae  that  feed  freely  upon  the  leaves, 
often  doing  great  damage  to  young  plantations.  These 
larvae  pupate  in  the  ground  and  soon  emerge  again  as 
adult  beetles. 

Various  methods  of  checking  Asparagus  Beetles  have 
been  found  successful  on  young  plantations.  Dusting  the 
vines  when  they  are  wet  with  dew  with  fresh,  dry  air-slaked 
lime  has  been  found  to  kill  the  larvae.  On  older  planta- 


THE  BEETLES:  ORDER  COLEOPTERA     137 

tions,  which  are  being  cut  over,  the  leaving  of  a  few  stalks 
as  trap  plants  to  attract  the  adult  beetles  when  they  lay 
their  eggs  has  been  found  effective.  These  trap  plants, 
of  course,  are  to  be  destroyed  often  enough  to  prevent  the 
eggs  from  hatching. 

A  much  more  familiar  and  widely  distributed  leaf  beetle 
is  the  common  Striped  Cucumber  Beetle,  which  is  found 
practically  everywhere  that  cucumbers,  melons,  squashes, 
or  related  plants  are  grown.  These  insects  pass  the 
winter  as  adults  under  such  shelter  as  they  may  find,  and 
in  spring  feed  ravenously  upon  the  young  cucumber  or 
other  plants.  They  also  deposit  their  eggs  about  the 
roots  of  these  plants,  and  the  eggs  shortly  hatch  into 
slender  larvae  that  feed  upon  the  roots.  In  this  way,  the 
beetles  not  only  threaten  the  crop  in  their  adult  state,  but 
they  often  do  a  more  serious,  though  less  recognized, 
damage  in  their  larval  state.  These  are  among  the  most 
difficult  of  all  pests  to  keep  in  check.  A  few  hills  may  be 
covered  with  netting  or  cloth.  The  liberal  use  of  refuse 
tobacco  powder  is  generally  also  an  efficient  protection. 
The  complete  destruction  of  all  squash,  cucumber,  melon, 
and  pumpkin  vines  as  soon  as  the  crop  is  gathered  is  a 
very  desirable  preventive  measure.  If  these  are  left,  the 
adult  beetles  find  abundant  food  up  to  the  time  they  go 
into  their  hibernating  quarters,  and  consequently  are .  in 
better  condition  to  survive  the  winter. 

A  closely  related  insect,  which  at  times  has  been  ex- 
ceedingly destructive,  is  the  Northern  Corn  Rootworm. 
This  is  a  small  beetle,  about  the  size  of  the  Cucumber 
Beetle,  but  of  a  uniform  pale  green  color.  In  the  larval 
state  it  feeds  upon  the  roots  of  corn  and  so  weakens  the 
plants  that  the  development  of  the  crop  is  greatly 
checked.  The  larvae  change  to  the  pupa  state  and 


138  FARM  FRIENDS  AND   FARM  FOES 

emerge  as  beetles  during  the  later  part  of  summer  or 
early  in  autumn. 

These  beetles  then  deposit  eggs  in  the  same  fields  in 
which  they  were  developed  and  the  eggs  remain  unhatched 
until  the  following  spring.  If  corn  is  then  planted,  the 
larvae  feed  again  upon  the  roots  and  repeat  the  injury  of 
the  season  before,  but  if  the  field  is  planted  to  some  other 
crop  upon  which  the  larvae  are  unable  to  develop,  the  in- 
sects will  die  and  the  damage  will  be  prevented.  Conse- 
quently this  Corn  Rootworm  has  been  a  blessing  in  disguise, 
for  it  has  compelled  those  farmers  who  were  depleting  the 
fertility  of  their  land  by  a  constant  succession  of  corn 
crops,  to  adopt  a  system  of  rotation.  The  discovery  of 
the  life  history  of  the  Northern  Corn  Rootworm  and  the 
pointing  out  of  the  fact  that  its  injuries  may  be  prevented 
by  the  rotation  of  crops  is  one  of  the  most  notable  ex- 
amples of  the  benefits  to  be  derived  from  scientific  ento- 
mology. The  credit  for  it  is  due  to  Dr.  S.  A.  Forbes,  the 
state  entomologist  of  Illinois. 

The  insect  known  in  many  of  the  Northern  states  as 
the  Twelve-spotted  Cucumber  Beetle,  is  also  known  in  the 
South  as  the  Southern  Corn  Rootworm.  Throughout  its 
range,  it  feeds  as  an  adult  upon  succulent  leaves,  and 
probably  develops  as  a  larva  upon  a  considerable  variety 
of  plant  roots.  In  Kentucky  and  some  other  Southern 
states  it  causes  much  damage  to  corn  crops.  Its  Southern 
life  history  is  briefly  this :  The  adult  beetles  hibernate  at 
the  surface  of  the  soil  or  just  below,  in  fields  of  clover,  al- 
falfa, and  other  crops.  They  come  forth  early  in  spring, 
and  as  soon  as  the  young  corn  plants  are  well  started,  they 
deposit  their  eggs  about  the  roots.  The  eggs  soon  hatch 
into  larvae  that  become  full  grown  early  in  summer,  chang- 
ing to  pupae  and  soon  again  into  adults  which  appear 


THE  BEETLES:  ORDER  COLEOPTERA     139 

about  midsummer.  In  a  short  time,  these  lay  eggs  for  a 
second  brood  of  larvae  that  develop  into  adult  beetles  in 
autumn.  These  beetles  hibernate  until  the  following 
spring.  There  are  thus  two  broods  of  larvae  each  season. 
The  fact  that  this  Southern  Corn  Rootworm  hibernates 
in  the  adult  condition  and  that  the  beetles  can  fly  freely 
from  place  to  place,  shows  at  once  that  this  pest  cannot  be 
checked  by  the  simple  method  of  rotation  that  serves  the 
purpose  in  the  case  of  the  Northern  Corn  Rootworm. 
Rotation  of  crops  will  be  helpful,  especially  if  care  is 
taken  not  to  plant  to  corn  those  fields  to  which  the  adult 
beetles  were  attracted  the  previous  autumn  by  an  abun- 
dant supply  of  succulent  food. 

FLEA  BEETLES 

There  are  several  species  of  Flea  Beetles  which  also  be- 
long to  this  leaf-beetle  family.  Some  of  the  larger  Flea 
Beetles  have  a  life  history  similar  to  that  of  the  Asparagus 
Beetle  and  the  Colorado  Potato  Beetle,  both  larvae  and 
adults  feeding  upon  the  foliage  of  the  food  plants.  The 
Grape  Flea  Beetle  is  an  excellent  example  of 
these  insects.  It  often  becomes  a  destructive 
pest  in  vineyard  regions. 

The  smaller  Flea  Beetles,  however,  are  more 
universally  distributed  and  affect  a  great  vari- 
ety of  cultivated  crops.  These  are  tiny  beetles 

; ,  .  ,  ,  ,  .  , .  ^  ,  FLEA  BEETLE 

which  are  able  to  jump  great  distances  when       Magnified 

disturbed,  and  which  are  only  too  commonly 
found  upon  potato,  tomato,  cabbage,  and  other  garden 
plants.  They  not  only  do  decided  damage  by  eating  out 
the  surface  of  the  foliage,  but  they  afford  an  easy  ingress 
for  the  germinating  spores  of  many  kinds  of  fungous  dis- 
eases. In  their  larval  state,  some,  at  least,  of  these  smaller 


140 


FARM   FRIENDS   AND    FARM   FOES 


Flea  Beetles  live  as  miners  in  the  leaves  and  stems  of  va- 
rious plants.  Spraying  with  Bordeaux  mixture  is  one  of 
the  best  methods  of  preventing  their  injuries. 

LONG-HORN  BEETLES 

The  so-called  Long-horn   Beetles  (Cerambycidae)  form 
one  of  the  most  important  groups  of  the  order.     The  adults 

have  cylindrical  bodies,  frequent- 
ly of  large  size,  with  feelers  or  an- 
tennae generally  as  long  as  the 
bodies  or  longer.  These  beetles 
deposit  their  eggs  upon  the  bark 
or  wood  of  a  great  variety  of  trees 
and  shrubs,  and  the  eggs  hatch 
into  footless  grubs  that  burrow 
into  the  bark  or  wood  of  the  host 
plant.  Some  of  the  most  destruc- 
tive fruit-tree  pests  belong  to  this 
family,  a  notable  example  being 
the  Round-headed  Apple-tree 
Borer,  which  is  often  very  injurious  in  apple  orchards. 

The  Locust  Borer  is  one  of  the  most  abundant  as  well 
as  most  beautiful  of  the  beetles  belonging  to  this  family. 
It  is  attractively  colored,  being  brown  or 
black,  marked  and  striped  with  lines  of 
light  yellow.  This  beetle  is  very  abun- 
dant in  late  summer  and  early  autumn 
upon  the  flowers  of  goldenrod,  which  it 
visits  in  search  of  pollen.  The  life  his- 
tory briefly  summarized  is  this :  The 
beetles  found  in  August  or  September 
deposit  their  eggs  one  at  a  time  in  the 
crevices  of  the  bark  of  the  common  or 


ROUND-HEADED  APPLE-TREE 

BORERS 
Beetle  and  Pupa 


LOCUST  BORER 
BEETLE 


THE  BEETLES:  ORDER  COLEOPTERA      141 

black  locust  trees.  In  about  ten  days  these  eggs  hatch 
into  tiny  larvae  that  excavate  slight  cells  in  the  bark ;  they 
remain  in  these  cells  throughout  the  winter.  Soon  after 
the  sap  begins  to  flow  the  following  spring,  the  larvae  be- 
come active  and  begin  to  burrow  through  the  bark  into  the 
wood.  The  burrows  that  they  make  are  commonly  not 
very  long  and  are  enlarged  as  the  insects  increase  in  size. 
The  larvae  become  full  grown  in  a  few  months,  and  change 
to  pupae  within  their  burrows  about  midsummer.  A  little 
later  they  change  again  to  adult  beetles  that  come  forth  to 
feed  upon  goldenrod  flowers  and  deposit  eggs  for  another 
generation  of  borers. 

The  characteristic  larvae  of  various  wood-boring  beetles 
are  very  often  to  be  seen  when  firewood  is  split  up,  dropping 
out  of  the  cylindrical  chambers  they  have  burrowed  in  the 
wood.  They  may  also  frequently  be  found  beneath  the 
bark  of  fallen  trees  or  in  the  partially  decayed  wood  of 
dead  stumps.  Some  species  are  much  more  destructive 
than  others,  but  in  general  their  life  histories  are  quite  simi- 
lar. The  Pine  Sawyer  is  a  large  species  that  breeds  in 
dead  pine  trees  and  often  causes  losses  of  millions  of 
dollars  in  a  single  year.  The  Oak  Twig  Pruner  is  another 
widespread  pest ;  it  may  commonly  be  found  in  fallen  twigs 
under  oak  trees. 

CURCULIOS    AND    OTHER    SNOUT    BEETLES 

Most  farmers'  boys  know  how  difficult  it  is  to  grow 
plums.  From  the  time  the  fruit  is  half  grown  until  it  is 
ripe  it  continues  to  fall  to  the  ground,  and  when  examined 
is  found  to  be  wormy  and  unfit  to  eat.  This  worminess 
is  generally  due  to  the  insect  known  as  the  Plum  Curculio, 
a  small,  hard-shelled,  brownish  beetle,  which  appears  among 
the  plum  trees  in  spring.  It  gnaws  holes  in  the  leaves, 


142 


FARM   FRIENDS   AND   FARM  FOES 


-Food  Puncture 
Larva 

Puncture 

PLUM 
CURCULIO 


the  flowers,  and  the  green  plums  to  satisfy  its  hunger.  The 
females  also  cut  crescent-shaped  holes  in  the  skin  of  the 
young  fruits  and  deposit  an  egg  beneath  each  of  the  cres- 
cent marks.  In  from 
three  to  seven  days  these 
eggs  hatch  into  little 
grubs  that  feed  upon  the 
pulp  of  the  fruit,  gradu- 
ally working  toward  the 
pit.  They  become  full- 
grown  in  two  or  three 
weeks.  The  infested 
plums  by  this  time  are 
so  injured  that  they  generally  fall  to  the  ground.  Then 
the  larvae  leave  the  fruit,  and  burrow  into  the  soil  about  an 
inch,  where  they  change  to  pupae.  Three  or  four  weeks 
later,  they  change  again  and  come  forth  as  perfect  beetles. 
There  is  but  one  brood  of  the  worms 
each  season.  The  adult  beetles  hiber- 
nate under  such  shelter  as  they  can  find 
at  the  surface  of  the  soil. 

The  Plum  Curculio  is.  by  no  means  an 
unmixed  evil.  In  many  localities  it  per- 
forms an  essential  service  by  thinning 
the  plums,  thus  saving  the  fruit  grower 
much  expense.  Besides  plums,  it  attacks 
peaches,  cherries,  apricots,  nectarines, 
apples,  and  pears.  In  the  case  of  the 
last  two  a  large  proportion  of  the  larvae 
appear  to  be  unable  to  develop  in  the 
green  fruit,  but  the  injuries  by  the  adult  beetles  often  cause 
the  fruits  to  be  dwarfed  and  gnarly. 

There  are  several  natural  enemies  of  the  Plum  Curculio. 


THE  BEETLES:  ORDER  COLEOPTERA 


PEACH 


One  of  the  most  efficient  of  these  is  the  tiny  fly  that  depos- 
its its  eggs  in  the  eggs  of  the  Curculio.  The  fly  eggs  hatch 
into  maggots  that  destroy  the  Curculio  eggs  and  mature  in 
a  few  days  into  other  flies  like  the  parent  parasites.  Conse- 
quently several  generations  of  these  egg  parasites  may 
follow  one  another  through  the  season. 
There  are  also  other  parasites  that  attack 
the  Curculio  larvae.  The  fluctuations  in 
the  abundance  of  the  Curculios  from  sea- 
son to  season  is  probably  due  chiefly  to 
these  parasitic  enemies. 

It  has  been  found  that  even  in  large 
orchards  the  injuries  of  the  Plum  Cur- 
culio may  be  prevented  to  a  great  ex- 
tent by  spraying  the  trees  with  arsenical 
poisons,  beginning  just  after  the  blossoms 
have  fallen.  The  adult  beetles  feeding 
upon  the  leaves  and  young  fruit  are  thus 
poisoned.  For  a  few  trees  this  method  is  not  always  so 
successful,  and  it  is  necessary  to  adopt  the  jarring  device. 
When  a  branch  upon  which  the  adult  beetles  are  resting  is 
shaken,  the  insects  fall  to  the  ground,  remaining  quiet  for 
some  time  afterward.  By  holding  sheets  stretched  upon 
wooden  frames  under  the  trees  and  then  shaking  the  latter, 
the  beetles  may  be  collected  in  numbers.  It  is  also  often 
advisable  to  supplement  the  spraying,  even  in  large 
orchards,  by  the  jarring  process.  The  destruction  of  the 
plums  as  fast  as  they  fall  and  the  cultivation  of  the  soil 
beneath  the  trees  during  the  summer  are  also  helpful 
measures. 

A  group  of  Snout  Beetles  that  at  times  has  proved 
very  destructive  in  the  great  corn-growing  regions  of  the 
Central  West,  is  that  of  the  Billbugs.  These  are  compara- 


BY 
CURCULIO 


I44  FARM   FRIENDS  AND   FARM  FOES 

tively  large  insects,  having  hard  bodies  with  long  snouts,  on 
the  ends  of  which  are  well-developed  jaws  by  means  of 
which  they  can  burrow  through  young  cornstalks  very 
quickly.  The  adult  beetles  feed  upon  the  tissues  of  these 
stalks,  greatly  weakening  the  plant  when  they  burrow 
through  it.  In  the  case  of  a  typical  species,  the  insect 
hibernates  in  the  adult  state,  and  attacks  the  young  corn 
soon  after  it  comes  up.  The  eggs  are  laid  in  early  sum- 
mer, commonly  about  the  bulbs  of  timothy  and  perhaps 
other  plants,  and  the  larvae  burrow  into  these  bulbs  and  there 
develop.  They  grow  rapidly  and  become  mature  beetles 
late  in  summer  or  early  in  autumn. 

Some  of  the  best-known  species  of  Billbugs  develop  as 
larvae  in  sedges  or  rushes  of  various  kinds.  Practically  all 
of  them  appear  to  breed  chiefly  on  low  lands  where  sedges 
are  likely  to  abound.  The  cornfields  often  injured  are 
those  upon  or  near  such  lands.  Fall  plowing  is  an  efficient 
preventive  of  injury  by  these  pests. 

COTTON  BOLL  WEEVIL 

The  Cotton  Boll  Weevil  has  attracted  more  attention 
during  recent  years  than  almost  any  other  destructive 

insect.       Migrating    into 
Texas  from  Mexico  about 
ADULT"  the  year   1890,  this  pest 

has  gradually  spread  to- 
MFYirAM  ward  the  north  and  east 

fand  threatens  to  become 
destructive  almost  every- 
WLEVIL  where     that     cotton     is 

LARVA  vvi_l_VIL  pupA 

grown.     Within  about  a 

EGG  dozen  years  of  its  intro- 

0  duction,  when  it  was  still 


THE  BEETLES:  ORDER  COLEOPTERA     145 

largely  confined  within  the  borders  of  Texas,  the  loss  to 
the  cotton  crop  in  one  year  due  to  this  insect  was  esti- 
mated at  $15,000,000  by  Dr.  L.  O.  Howard,  entomologist 
of  the  United  States  Department  of  Agriculture.  The 
possible  annual  loss  to  the  cotton  planters  of  the  South 
in  case  the  pest  should  be- 
come generally  distributed, 
has  been  estimated  at 
$250,000,000.  Conse- 
quently it  is  not  strange 
that  this  insect  has  received 
a  great  deal  of  attention 
from  the  national  and  state 
governments,  and  that 
strenuous  efforts  are  being 
made  to  destroy  it  where 
it  now  exists,  and  to  pre- 
vent its  introduction  into 
new  localities. 

Briefly   stated,    the   life  INFESTED  COTTON  SQUARE 

history  of  the  Boll  Weevil  is  this  :  The  adult  snout  beetles 
pass  the  winter  in  a  great  variety  of  shelters,  in  or  near 
the  cotton  fields.  In  spring  they  come  forth  from  their 
hibernating  quarters  and  attack  the  young  plants,  feeding 
upon  the  buds,  in  which  they  make  small  round  holes.  In 
some  of  these  holes  are  deposited  eggs  that  soon  hatch 
into  whitish,  footless  grubs  that  feed  upon  the  interior  of 
the  buds,  destroying  the  blossoms  and  thus  greatly  injuring 
the  prospects  of  the  crop.  These  larvae  grow  rapidly  and 
in  a  few  weeks  become  mature,  so  far  as  this  stage  is  con- 
cerned. They  then  change  to  pupae  still  within  the  shelter 
of  the  bud,  and  a  little  later  change  to  adult  beetles.  They 
gnaw  their  way  out  and  soon  deposit  eggs  for  a  second 


146  FARM  FRIENDS  AND    FARM  FOES 

brood  of  larvae.  There  are  several  broods  during  the  sea- 
son, the  larvae  being  able  in  the  hot  weather  of  midsummer 
to  become  full  grown,  so  far  as  the  larval  stage  alone  is 
concerned,  in  one  week.  The  later  broods  develop  within 
the  cotton  bolls  and  thus  cause  a  vast  amount  of  damage. 

The  Boll  Weevils  continue  to  multiply  through  the  fall 
upon  any  plants  that  are  still  present  in  the  fields,  and  those 
which  hibernate  most  successfully  are  the  ones  that  develop 
latest  in  the  season.  Consequently,  as  a  result  of  many 
careful  observations  and  experiments,  it  is  pretty  certainly 
established  that  the  most  effective  practical  remedy  for  the 
insect  is  to  pull  up  and  burn  all  the  cotton  plants  present 
in  the  fields  in  autumn.  This  may  usually  be  done  by  cut- 
ting off  the  roots  with  a  plow  and  then  at  once  gathering 
the  plants  by  hand  and  piling  them  in  windrows  where  they 
will  rapidly  dry  out,  and  in  about  two  weeks  may  be  burned. 
The  addition  of  a  little  crude  oil  is  sometimes  desirable  to 
insure  the  complete  destruction  of  all  the  stalks.  In  an  in- 
teresting experiment  conducted  by  the  Department  of  Agri- 
culture, an  isolated  cotton-growing  region  of  about  four  hun- 
dred acres  was  thus  treated  in  autumn,  with  the  result  that 
the  beetles  were  nearly  all  destroyed  and  the  following  season 
the  amount  of  damage  done  by  them  was  insignificant. 

Fall  plowing  is  often  a  desirable  procedure  in  cotton 
culture  whether  the  Boll  Weevils  are  present  or  not,  and  so 
it  seems  that  this  pest,  like  so  many  others,  will  bring  about 
an  improvement  in  agricultural  methods. 

OBSERVATIONS   FOR  PUPILS 
PLUM  CURCULIO 


i .    Pick  up  some  green  plums  from  beneath  the  trees.    Can  you  find  any 
of  the   crescent-shaped    marks   where  the   Curculios   have  laid  their 


THE  BEETLES:  ORDER  COLEOPTERA     147 

eggs  ?     Can  you  find  any  holes  where  the  Curculios  have  been  simply 
feeding? 

2.  Cut  open  some  of  the  fallen  plums.     Can  you  find  eggs  or  larvae 
in  the  green  pulp  ?     Can  you  trace  the  holes  made  by  the  larvae  in  bur- 
rowing through  the  pulp? 

3.  Place  a  few  freshly  fallen  plums  on  two  or  three  inches  of  garden 
soil  in  the  bottom  of  a  glass  jar  or  a  wooden  box.     A  week  later  see  if 
you  can  find  any  larvae  or  pupae  in  the  soil.     Leave  some  of  them  and 
see  if  you  can  rear  the  adult  beetles. 

4.  Hold  a  sheet  or  a  large  piece  of  paper  under  a  plum  tree  and  jar 
the  limbs  above.     See  if  you  can  get  any  of  the  Curculios  in  this  way. 
You  may  know  them  by  their  hard  shells  and  curious  snouts.     Place  a 
few  of  them  under  a  bell  glass  with  a  branch  of  green  plums  held  in  a 
bottle  of  water.     Watch  the  beetles  eating  and  ovipositing. 

5 .  Examine  peaches,  cherries,  apples,  and  pears  to  find  similar  injuries 
of  the  Curculios.     Do  you  find  any  live  Curculio  larvae  in  green  apples 
and  pears  ? 

B 

1 .  Write  or  tell  a  little  story  with  this  title :  The  Life  of  the  Plum 
Curculio.     Follow  this  outline  :  — 

The  beetle  in  winter. 

The  beetle  in  spring. 

The  laying  of  the  egg. 

The  hatching  of  the  egg. 

The  growth  of  the  larva. 

The  change  to  the  pupa. 

The  change  to  the  adult. 

Remedies  for  injuries  by  Curculios. 

2.  Make  some  or  all  of  these  drawings :    A  plum  showing  feeding 
holes  and  crescent  holes ;    a  section  of  an  injured  plum  with  larva  in- 
side ;  an  apple  or  a  peach  injured  by  Curculios. 

3.  Read  Circular  73,  U.  S.  Bureau  of  Entomology. 

MAY  BEETLES 

1 .  Have  you  ever  seen  white  grubs  in  the  soil  turned  over  in  plow- 
ing or  spading  ? 

2.  Are  these  grubs  more  likely  to  be  found  in  sod  land  than  in  that 
which  has  been  cultivated  for  several  years  ? 


148  FARM  FRIENDS  AND   FARM  FOES 

3.  Did  you  ever  see  the  fully  developed  beetles  in  freshly  plowed 
ground  ?      At  what  seasons  are  they  found  ? 

4.  Collect  some  of  the  beetles  that  fly  about  during  the  evenings  in 
May  or  June.     Kill  them  in  a  cyanide  bottle.      Study  their  structure. 
How  do  they  differ  from  grasshoppers  ? 

5.  When  the  beetles  are  thick,  try  putting  a  lantern  outdoors  over  a 
tub  of  water  with  a  bit  of  kerosene  on  top.      See  how  many  beetles  are 
killed  in  this  way.      Write  or  tell  the  story  of  the  life  history  of  the 
May  Beetle.      Make  some  drawings  to  illustrate  the  story. 

COTTON  BOLL  WEEVIL 

1.  If  you  live  in  a  cotton-growing  region,  find  out  whether  the  Boll 
Weevil  is  present.      If  so,  learn  how  long  since  it  first  appeared  in  your 
locality. 

2.  See  what  stages  of  the  weevils  you  can  find. 

3.  Look  especially  in  cotton  fields  in  fall  to  see  whether  any  of  the 
pests  are  hibernating  there. 

4.  Learn  what  methods  of  preventing  injury  by  weevils  have  been 
adopted  by  the  cotton  growers. 

5.  Write  a  little  story  with  this  title:  What   I    Know  about  Boll 
Weevils.      Illustrate  it  with  drawings. 

6.  Read  the  account  of  the  Cotton  Boll  Weevil  in  Farmers1  Bulletin 

344- 

ROSE   CHAFER 

1 .  At  what  season  do  you  find  the  first  Rose  Chafers  ? 

2.  What  plants  do  they  attack  most  seriously  in  your  region? 

3.  Are  there  extensive  sandy  lands  near,  where  the  larvae  may  de- 
velop ? 

4.  Why  is  it  probable  that  few  birds  would  eat  these  beetles  ? 

OTHER  BEETLES 
Read  such  of  the  following  references  as  your  teacher  directs  :  — 

The  Corn  Rootworms,  Circular  54,  U.  S.  Bureau  of  Entomology.  The 
Clover  Root-borer,  Circular  67,  U.  S.  Bureau  of  Entomology.  The  Colorado 
Potato  Beetle,  Circular  87,  U.  S.  Bureau  of  Entomology.  The  Fruit-tree  Bark- 
beetle,  Circular  29,  U.  S.  Bureau  of  Entomology.  The  Larger  Apple-tree 
Borers,  Circular  32,  U.  S.  Bureau  of  Entomology. 


CHAPTER   XI 
Hymenoptera :  the  Ants,  Bees,  Wasps,  and  Sawflies 

THE  ants,  bees,  wasps,  and  sawflies,  with  other  related  in- 
sects, form  one  of  the  most  characteristic  of  all  the  orders. 
It  is  called  Hymenoptera,  and  its  members  may  be  known  by 
the  fact  that  they  pass  through  complete  transformations, 
and  that  the  adults  generally  have  four  more  or  less  trans- 
parent membranous  wings,  of  which  the  front  pair  is  the 
larger.  The  mouth  parts  are  formed  for  biting,  but  there 
is  commonly  present  also  a  tongue  by  means  of  which  the 
insects  can  suck  or  lap  up  liquids.  In  the  case  of  the 
higher  members  of  this  order,  the  larvae  feed  upon  a  special 
food  prepared  by  the  adults. 

SAWFLIES 

As  very  few  of  the  Hymenoptera  feed  on  plant  tissues, 
a  comparatively  limited  number  of  injurious  species  are 
found  in  the  order.     Of  these  the  most  im- 
portant belong  to  the  great  family  of  Sawflies 
(Tenthredinidae)  which  are  characterized  by 
having  an  ovipositor  by  means  of  which  the 
insects  are  able  to  cut  holes  in  vegetable  tis-    CHERRY  SAW- 

FLY    Magnified 

sues  for  the  insertion  of  their  eggs.  The 
eggs  are  commonly  laid  within  such  cavities,  but  sometimes 
they  are  deposited  along  the  outer  surface  of  leaf  or  stem. 
They  soon  hatch  into  caterpillar-like  larvae,  commonly 
called  false  caterpillars  or  slugs,  which  feed  upon  the  foli- 
age and  finally  spin  cocoons  within  which  they  change  to 

149 


FARM  FRIENDS  AND  FARM  FOES 


pupae,  and  change  again  later  into  adult  sawflies.  The 
sawfly  larvae  have  three  pairs  of  true  legs  and  six  to  eight 
pairs  of  prolegs.  Most  of  them  have  the  abdomen  curved 
inward  in  the  curious  way  shown  in  the 
picture  of  the  Willow  Sawfly  larva. 

The  Common  Currant  Worm  is  one  of 
the  most  familiar  of  the  sawflies,  and  its 
life  history  fairly  illustrates  that  of  many 
related  species.  The  small  whitish  glassy 
eggs  are  deposited  in  spring  upon  the 
principal  veins  of  the  under  side  of  the 
lower  leaves  of  currants  and  gooseberries. 
In  about  ten  days  these  eggs  hatch  into 
small  whitish  grubs  or  larvae  that  eat  cir- 
cular holes  in  the  leaves.  After  a  few 
days  they  cast  their  skins  or  molt  —  a 
.process  that  is  repeated  several  times  dur- 
ing the  next  six  weeks.  In  color  they 
change  from  whitish  to  plain  green,  but 
soon  become  dotted  with  black,  a  color  condition  that  con- 
tinues until  the  last  molt,  when  they  change  to  light  green 
with  a  little  yellow  on  some  parts  of  the  body.  As  they 
grow  older  the  injury  to  the  leaves  increases,  and  in  severe 
attacks  the  bushes  are  completely  defoliated. 

When  fully  grown  in  the  larval  stage,  the  Currant  Worms 
descend  to  the  ground,  seeking  shelter  beneath  the  leaves 
and  rubbish.  There  they  spin  tough,  brown,  silken  cocoons 
within  which  they  change  to  pupae.  A  short  time  later 
they  again  change  to  four-winged  flies.  These  come  forth 
early  in  summer  and  deposit  eggs  for  a  second  brood  of 
larvae,  most  of  which  pass  the  following  winter  within  their 
cocoons. 

The  eggs  of  the  Currant  Worm,  small  as  they  are,  are 


WILLOW  SAWFLY 
LARVA 


ANTS,  BEES,   AND  WASPS  151 

infested  by  a  tiny  parasite  that  develops  in  them.  An  ex- 
ceedingly minute  fly  deposits  its  eggs  within  the  eggs  of 
the  Currant  Worm  —  one  in  each.  The  former  hatch  into 
tiny  footless  larvae  that  develop  at  the  expense  of  the 
material  of  the  Currant  Worm  egg.  Finally  these  larvae 
pupate  and  later  change  to  tiny  adult  flies. 

This  Currant  Worm  was  originally  a  native  of  Europe, 
having  been  introduced  into  America  many  years  ago.  Its 
injuries  may  be  prevented  by  spraying  or  dusting  the 
bushes  with  hellebore  when  the  larvae  are  young.  It  should 
not  be  applied  when  the  fruit  is  ripening. 

In  addition  to  the  Currant  Worm,  there  are  a  number 
of  other  insects  belonging  to  this  group.  A  very  similar 
species  feeds  upon  the  foliage  of  raspberries  and  is  called 
the  Raspberry  Sawfly.  Another  feeds  upon  strawberry 
leaves  and  is  called  the  Strawberry  Sawfly.  Still  an- 
other, which  is  an  unusually  large  species,  feeds  upon 
willow  and  is  called  the  Willow  Sawfly.  A  very  character- 
istic form  often  injures  grape  leaves  and  is  sometimes 
called  the  Grape  Slug. 

Two  similar  and  characteristic  sawfly  larvae  are  found 
upon  pears,  plums,  and  cherries,  and  upon  roses.  These 
have  in  their  younger  stages  curious  slimy  skins  and  eat 
only  the  surface  of  the  leaves,  causing  a  characteristic  and 
easily  recognized  injury.  The  presence  of  this  slimy  coat- 
ing enables  one  to  kill  them  readily  by  applying  almost  any 
fine  powder,  such  as  road  dust  or  air-slaked  lime  to  the  af- 
fected foliage.  The  particles  will  adhere  to  the  larvae  and 
eventually  cause  their  death. 

Most  of  these  false  caterpillars  are  marked  in  colors  of 
striking  contrast  which  indicate  that  they  have  some  method 
of  defense  from  birds.  They  are  thus  examples  of  what 
the  naturalists  call  warning  coloration,  and  they  seem  to 


152  FARM   FRIENDS   AND   FARM   FOES 

be  comparatively  little  injured  by  birds.  All  of  them,  how- 
ever, are  easily  destroyed  by  spraying  with  arsenical  poisons 
or  even  with  insect  powder  or  hellebore. 

FOUR-WINGED  GALLFLIES 

The  next  most  important  group  of  injurious  insects  be- 
longing to  the  Hymenoptera  is  that  of  the  Gallflies  (Cyni- 
pidae).  There  are  many  species  of  these  insects  which 
affect  almost  every  sort  of  tree,  shrub,  and  herbaceous 
plant,  but  comparatively  few  of  them  are  destructive  to 
cultivated  crops. 

One  of  the  most  familiar  of  these  injurious  insects  is  the 
species  that  makes  its  home  in  blackberry  canes,  causing  a 
large  abnormal  swelling  upon  the  cane  which  is  commonly 
called  the  pithy  Blackberry  Gall.  The  small  four-winged 
Gallfly  deposits  its  eggs  in  the  growing  stem,  a  large 
number  of  eggs  being  placed  near  together.  These  hatch 
into  tiny  larvae  which  bring  about  an  abnormal  growth  of 
the  blackberry  tissues  that  eventually  takes  the  form  of  the 
curious  gall.  If  you  cut  one  of  these  open,  you  are  likely 
to  find  a  great  many  little  cells  in  which  the  larvae  are 
living.  They  finally  transform  to  pupae  within  these  cells, 
and  emerge  later  as  adult  flies.  The  cutting  and  burning 
of  all  affected  stalks  in  winter  will  help  to  check  the  increase 
of  these  insects. 

A  great  many  forms  of  Gall  insects  may  be  found  at  al- 
most any  time  upon  the  willows  and  the  oaks.  The  familiar 
oak  apples  are  excellent  examples  of  the  sort  of  abnormal 
vegetation  growth  caused  by  the  Gallflies. 

CHALCID  FLIES 

The  great  family  of  small  parasitic  flies,  called  the  Chalcid 
family,  consists  for  the  most  part  of  insects  that  live  in  their 


ANTS,   BEES,   AND  WASPS  153 

larval  stages  upon  other  insects.  A  very  few,  however, 
develop  at  the  expense  of  vegetable  tissues.  The  Wheat 
Jointworm,  of  the  genus  Isosoma,  is  the  most  notable  ex- 
ample of  the  latter.  The  adult  of  this  is  a  small  fly 
which  deposits  its  eggs  in  the  wheat  stem  at  or  near  a  joint. 
The  egg  hatches  into  a  tiny  footless  larva,  which  absorbs 
the  sap  of  the  plant,  causing  the  tissue  to  harden  and  the 
growth  of  the  wheat  to  be  injured.  The  larva  finally  ma- 
tures into  a  pupa  and  again  into  an  adult  fly.  When  it  is 
present  in  large  numbers,  it  may  seriously  injure  the 
wheat  crop,  but  it  is  comparatively  easily  destroyed  by  any 
procedure  that  causes  the  destruction  of  the  stalks  contain- 
ing larvae  or  pupae.  The  burning  of  the  wheat  stubble  is 
one  effective  remedial  measure. 

OBSERVATIONS   FOR   PUPILS 
IMPORTED  CURRANT  WORM 

1 .  In  spring  or  summer  examine  the  leaves  of  currant  and  gooseberry 
bushes  carefully  for  the  eggs  upon  the  under  side  of  the  midrib  and 
secondary  veins.     Do  you  suppose  all  the  eggs  on  one  leaf  are  deposited 
by  one  sawfly? 

2.  If  you  find  any  leaves  with  eggs  upon  them,  place  the  leaf  in  a 
vivarium  with   the  stem  inserted  in  a  bottle  of  water.     Watch  for  the 
hatching  of  the  larvae,  and  feed  them  fresh  leaves  from  day  to  day. 

3.  Look  at  the  lower  leaves  on  the  currant  bushes  to  find  some  with 
round  holes  in  them.     Are  there  any  currant  worms  at  work  on  such 
leaves  ? 

4.  Raise   a   few  currant  worms  in  a  jelly  glass   or  other  vivarium. 
Note  the  changes  of  color  from  time  to  time.     Can  you  find  the  cast 
skins  after  molting  ?    Do  the  caterpillars  stop  eating  and  rest  before  and 
after  molting  ?     Where  does  the  skin  split  open  before  it  is  cast  off  ? 

5.  Examine  carefully  the  legs  on  a  good-sized  currant  worm.     Are 
they  all  alike  ?     Which  are  more  pointed  ?     How   many  legs  in  all  ? 
Watch  the  insect  as  it  crawls,  and  notice  how  the  legs  are  used. 

6.  When  the  larvae  spin  their  cocoons,  notice  the  texture  of  these. 


154 


FARM   FRIENDS  AND   FARM  FOES 


Is  it  like  the  texture  of  a  moth  cocoon  ?     Are  they  water-tight  ?     Can 
you  find  any  cocoons  out  of  doors  beneath  infested  currant  bushes  ? 

7.  Cut  open  a  cocoon  in  which  the  insect  has  pupated  and  find  the 
pupa  and  the  cast  skin.     Compare  this  pupa,  especially  in  regard  to  the 
distinctness  of  the  legs  and  other  appendages  with  the  pupa  of  a  moth 
or  butterfly. 

8.  Observe  how  the  fly  escapes  from  the  cocoon.     Does  it  gnaw  off 
a  cap  ?     Compare  it  with  a  bee  or  a  wasp  and  then  with  a  two-winged 
fly.     Study -its  structural  characters. 

9.  Give  either  orally  or  in  writing  a  short  account  of  the  life  of  the 
Currant  Worm.     This  outline  may  help  :  — 

The  laying  of  the  eggs. 
The  hatching  of  the' eggs. 
The  growth  of  the  caterpillar. 
The  spinning  of  the  cocoon. 
The  change  to  the  pupa. 
The  change  to  the  adult  fly. 

10.  Make  these  drawings  :    A  leaf  with  round  holes  made  by  young 
larvae  ;  leaf  badly  eaten  ;  a  larva,  side  view ;  a  cocoon ;  an  adult  sawfly. 

OTHER  INSECTS 
Read  such  of  the  following  references  as  your  teacher  may  direct :  — 

The  Joint  Worm,  Circular  66,  U.  S.  Bureau  of  Entomology.     Insect  Enemies 
of  Growing  Wheat,  Farmers'  Bulletin,  132. 


CHAPTER   XII 


Insecticides  and  their  Application 

IT^  is  well  known  that  there  are  two  principal  ways  in 
which  plant-feeding  insects  get  their  food.  Some  insects 
bite  or  chew  the  parts  of  the  plants  upon  which  they  feed, 
while  others  are  provided  with  a  hollow  beak  that  they 
push  into  the  tissues  of  the  plant  to  suck  the  sap.  All  the 
leaf-eating  caterpillars  are  examples  of  the  biting  insects, 
while  the  plant  lice,  squash  bug,  and  many  related  species 
are  examples  of  the  sucking  insects.  The  picture  below 
shows  the  way  in  which  the  sucking  mouth  parts  of  the 
plant  louse  are  inserted  among  the  cells  of  plant  tissues. 

This  essential  difference  in  the  feeding  habits  of  insects 
must  be  considered  when  we  try  to  kill  them  by  the  appli- 
cation of  insecticides.  In  the  case  of  a 
biting  insect,  we  may  hope  to  poison  it 
by  placing  fine  particles  of  arsenic  in  some 
form  upon  the  leaves  of  the  food  plant. 
As  the  insect  bites  the  leaves,  it  will  be 
likely  to  eat  some  of  these  particles  and 
be  killed.  But  in  the  case  of  a  sucking 
insect,  we  must  use  some  insecticide  that 
will  kill  by  coming  in  contact  with  the 
insect  itself.  Such  insecticides  commonly 
act  by  reaching  the  interior  of  the  insect 
through  the  breathing  pores,  or  trachea, 
and  so  they  are  sometimes  called  tracheal  poisons  to  dis- 
tinguish them  from  the  ordinary  internal  poisons.  Kero- 


HEAD     OF     APHIS 

SHOWING  SUCKING 

TONGUE      AMONG 

PLANT   CELLS 

Magnified 


FARM   FRIENDS   AND   FARM   FOES 


sene,  whale-oil  soap,  and  pyrethrum  or  insect  powder  are 
among  the  most  important  tracheal  poisons. 

Some  plant-feeding  larvae  have  such  slimy  skins  that  they 
are  readily  killed  by  dusting  with  powdered  air-slaked  lime, 
or  ashes.  The  "  slugs  "  on  pear,  cherry,  and  rose  leaves 
are  examples  of  these. 

INTERNAL  POISONS 

The  poisons  most  commonly  used  against  biting  insects 
are  certain  chemical  compounds  composed  in  part  of  ar- 
senic. Arsenate  of  lead,  arsenite  of  lime,  and  Paris  green 
are  notable  examples  of  such  insecticides. 

For  a  long  time  Paris  green  was  the  most  important  of 
the  arsenical  insecticides.  It  is  a  chemical  combination  of 
arsenic  and  copper,  containing,  when  pure,  about  fifty-five 
per  cent  of  arsenic.  It  is  in  a  finely  powdered  condition, 
and,  when  placed  in  water,  the  fine  particles  do  not  dis- 
solve, but  remain  in  suspension.  Because  of  this  fact,  one 
of  the  most  popular  ways  of  applying  arsenical  poisons  to 
plants  in  danger  from  the  attacks  of 
biting  insects,  is  in  a  water  mixture 
by  means  of  a  force  pump  and  spray 
nozzle. 

In  its  simplest  form  this  process 
consists  of  mixing  about  a  teaspoon- 
ful  of  the  poison  in  a  pail  of  water, 
stirring  thoroughly  to  get  the  powder 
evenly  distributed  through  the  water. 
A  small  force  pump,  to  which  is  at- 
tached a  rubber  tube  with  a  spray 
nozzle  at  the  end,  is  then  set  in  the  pail.  By  working  the 
handle  of  the  pump,  the  water  with  the  poison  particles 
in  suspension  is  forced  through  the  tube  and  nozzle,  corn- 


Bucket 
Pump 


INSECTICIDES   AND   THEIR  APPLICATION        157 

ing  from  the  latter  in  a  mistlike  spray.  This  spray  is  di- 
rected upon  the  leaves  of  the  plant  to  be  protected,  covering 
each  leaf  with  the  liquid. . 

As  soon  as  the  spraying  ceases,  the  water  begins  to  evap- 
orate and  rapidly  disappears,  leaving  the  particles  of  poison 
more  or  less  evenly  distributed  over  the  foliage.  There 
they  remain  for  some  time,  so  that  in  case  a  biting  insect 
feeds  upon  the  poisoned  surface  it  will  eat  some  of  these 
particles  and  be  killed. 

Fortunately  the  insoluble  poison  is  not  absorbed  into 
the  tissues  of  the  plant,  so  that  the  process  can  gener- 
ally be  carried  on  without  danger  to  the  consumers  of 
the  crop.  In  the  course  of  a  few  weeks  the  particles  of 
poison  are  washed  away  by  rain  or  dew,  or  blown  away 
by  the  wind,  or  dissipated  through  the  action  of  the  sun- 
shine. 

A  substance  that  is  used  to  destroy  insects  is  called  an 
insecticide  or  insect  killer.  Thus  Paris  green  is  an  insecti- 
cide. So  also  is  lead  arsenate,  hellebore,  powdered  to- 
bacco, and  insect  powder.  Each  of  these  substances  may 
be  applied  to  plants  in  mixture  with  water,  or  most  of  them 
may  be  dusted  on  in  the  form  of  a  dry  powder.  One  may 
sometimes  use  for  this  purpose  simply  a  porous  bag,  out  of 
which  the  powder  is  sifted.  It  is  better,  however,  to  apply 
the  material  by  means  of  one  of  the  many  kinds  of  powder 
bellows  manufactured  for  this  purpose.  With  one  of  the 
better  forms  of  these,  a  pound  of  Paris  green  can  be  evenly 
distributed  over  an  acre  of  potato  vines. 

Paris  green  is  so  powerful  a  poison  that  it  is  often  de- 
sirable to  dilute  it  with  some  substance  like  land  plaster, 
air-slaked  lime,  or  flour.  The  proportion  of  poison  to  dilu- 
ent varies  greatly  with  different  users.  One  part  of  poison 
to  twenty  parts  of  diluent  serves  the  purpose  if  the  mixing 


158  FARM   FRIENDS  AND   FARM   FOES 

be  thoroughly  done.     When  a  good  powder  gun  is  used,  it 
is  not  so  necessary  to  dilute  the  poison. 

During  recent  years,  arsenate  of  lead  has  become  one  of 
the  most  generally  used  of  arsenical  insecticides.  It  is 
made  by  combining  arsenate  of  soda  with  acetate  of  lead 
in  water,  and  is  commonly  offered  for  sale  in  the  form  of 
a  thick  paste.  This  insecticide  has  a  great  advantage  over 
Paris  green  in  that  it  may  be  applied  even  to  tender  foliage 


A  SIMPLE  SPRAYING  OUTFIT 

without  injury  to  the  plant.  It  also  remains  upon  the  leaves 
longer  than  any  other  arsenical  insecticides.  Under  special 
conditions  it  may  be  advisable  to  prepare  the  arsenate  of  lead 
at  home,  but  usually  this  is  scarcely  worth  while.  A  dry, 
powdery  form  of  this  poison  has  lately  been  put  upon  the 
market,  and  is  likely  to  be  very  useful  for  applying  with 
various  sorts  of  powder  bellows. 

Trouble  has  been  observed  in  some  Western  states  in 
injury  to  the  health  of  trees  from  the  use  of  arsenate  of  lead. 
The  poison  appears  to  penetrate  the  soil  and  be  absorbed 
through  the  roots.  On  this  account  arsenic  sulphide  has 
been  substituted  in  an  experimental  way,  and  promises  to  be- 
come an  important  insecticide.  It  is  less  soluble  than  other 
forms  of  arsenic,  and  also  less  expensive. 


INSECTICIDES  AND   THEIR  APPLICATION        159 

EXTERNAL  POISONS 

The  petroleum  oils  are  among  the  most  important  of  the 
contact-killing  insecticides.  For  general  use  kerosene  is 
the  most  convenient  of  these  oils.  As  kerosene  does  not 
mix  with  water,  dilution  with  this  liquid  is  not  practicable. 
It  has  been  found,  however,  that  kerosene  may  be  safely 
and  effectively  used,  provided  it  is  first  emulsified  with  hot 
soapsuds.  This  is  generally  accomplished  by  adding  two 
gallons  of  kerosene  to  one  gallon  of  a  solution  made  by  dis- 
solving half  a  pound  of  common  hard  soap  in  one  gallon 
of  boiling  water,  and  then  churning  the  mixture  by  forcing 
it  back  into  the  same  vessel  through  a  force  pump.  A 
creamy  emulsion  will  thus  be  formed.  Before  it  is  ap- 
plied, this  emulsion  is  to  be  diluted  with  nine  or  ten  parts 
of  water.  It  is  better  to  use  soft  water  or  rain  water  for 
the  dilution. 

The  undiluted  emulsion  may  be  kept  for  some  time,  stored 
in  a  dark,  cool  place.  When  needed,  the  required  amount 
may  be  measured  out  and  mixed  with  three  or  four  parts 
of  boiling  water,  cold  water  being  added  to  fill  out  the  di- 
lution. 

Kerosene  emulsion  is  an  excellent  remedy  for  insects 
that  suck  the  sap  of  plants  through  pointed  beaks,  such  as 
the  plant  lice  and  the  chinch  bugs.  It  kills  by  contact,  but 
does  not  remain  upon  the  plant  in  an  effective  condition. 
It  is  applied  in  a  fine  spray. 

Various  forms  of  crude  petroleum  have  recently  come 
into  use  against  scale  insects.  Some  proprietary  insecti- 
cides contain  heavy  oils  so  treated  as  to  mix  readily  with 
water,  so  that  they  are  very  easy  to  spray  upon  dormant 
trees. 

The  lime-sulphur  wash  is  one  of  the  most  efficient  con- 


160  FARM  FRIENDS  AND   FARM  FOES 

tact-killing  insecticides.  It  is  used  chiefly  on  dormant  trees 
to  kill  the  San  Jose"  scale  and  other  scale  insects.  The 
usual  formula  is  :  Unslaked  lime,  20  pounds ;  sulphur, 
15  pounds;  water,  50  gallons.  The  lime  is  slaked  in  10  or 
1 5  gallons  of  water ;  then  the  sulphur  is  added  and  the  prep- 
aration boiled  for  an  hour.  The  rest  of  the  water  is  then 
added  and  the  mixture  is  ready  for  use  on  dormant  trees 
only. 

In  place  of  this  mixture  boiled  by  outside  heat,  lime-sul- 
phur washes  have  lately  been  made  by  utilizing  the  heat  of 
the  slaking  lime.  These  are  called  self-boiled  mixtures  and 
usually  have  less  sulphur  and  lime  than  the  formula  given 
above.  They  are  often  used  for  summer  spraying,  being 
effective  against  both  scale  insects  and  various  fungous 
diseases. 

Strong  soapsuds  have  a  decided  insecticide  value  for  use 
against  plant  lice  and  other  soft-bodied  insects.  Whale-oil 
soaps  are  more  effective  than  ordinary  soaps,  and  are  gen- 
erally used  as  insecticides. 

Pyrethrum  powder  commonly  sold  as  insect  powder  is 
a  standard  insecticide  for  use  against  house  flies  and  cer- 
tain other  insects.  It  consists  of  the  powdered  flower- 
heads  of  the  pyrethrum  plants  —  a  genus  of  composite 
flowers  which  are  often  grown  in  gardens  for  their  orna- 
mental value.  This  powder  is  generally  used  dried,  but 
may  be  applied  as  a  spray  —  by  mixing  one  ounce  of  pow- 
der with  two  gallons  of  water  and  letting  it  stand  over 
night,  or  by  boiling  for  a  few  minutes. 

Tobacco  is  another  contact-killing  insecticide  which  is 
frequently  used  with  good  results  against  plant  lice  and 
vermin  on  domestic  animals.  The  refuse  stems  are  some- 
times utilized  in  greenhouses  as  a  mulch  for  growing  crops 
to  prevent  the  development  of  aphides.  These  stems  are 


INSECTICIDES   AND   THEIR  APPLICATION        161 


also  ground  into  a  powder  which  is  applied  directly  to  the 
insects.  A  tobacco  decoction  is  frequently  made  by  boil- 
ing the  powder  or  stems 
in  water  or  by  pouring 
boiling  water  over  them. 
There  is  thus  formed  a 
concentrated  solution 
which  is  diluted  with  cold 
water  until  there  are  about 
two  gallons  of  decoction 
for  each  pound  of  tobacco 
used.  The  decoction  may 
be  sprayed  upon  the  in- 
sects to  be  killed.  Per- 
haps the  way  in  which  tobacco  is  most  commonly  used  as 
an  insecticide  is  that  of  slowly  burning  the  stems  in  green- 
houses, producing  a  smoke  which  permeates  the  plants 
and  kills  the  pests  upon  them. 


VAPORS  AND  GASES 

There  are  certain  insects  which  may  most  easily  be 
killed  by  the  use  of  vapors  or  gases.  For  this  purpose 
bisulphide  of  carbon  and  hydrocyanic  acid  gas  are  chiefly 
employed.  The  former  is  a  liquid  that  readily  volatilizes 
on  exposure  to  the  air  and  kills  all  insects  with  which  it 
comes  in  contact.  It  is  used  to  best  advantage  against  in- 
sects affecting  dry  seeds  and  grains  in  storehouses,  and 
against  insects  affecting  the  roots  of  plants. 

Hydrocyanic  acid  gas  is  a  deadly  vapor  made  by  pouring 
sulphuric  acid  on  cyanide  of  potassium.  It  is  used  to  de- 
stroy white  flies  in  greenhouses  and  for  various  enemies  of 
citrus  fruits  in  Florida  and  California.  In  the  case  of 


162  FARM   FRIENDS  AND   FARM  FOES 

these  fruits,  tents  are  placed  over  the  trees  before  the  gas 
is  generated. 

In  California  sulphur  is  used  as  a  remedy  for  red  spiders 
and  certain  leaf  hoppers.  The  sulphur  vaporizes  in  the 
hot  sunshine,  and  the  fumes  are  fatal  to  the  insects.  In 
greenhouses  sulphur  is  also  used  by  painting  heating  pipes 
with  it  so  that  the  fumes  will  be  given  off. 

OBSERVATIONS   FOR   PUPILS 

1.  Make  a  list  of  the  injurious  plant-feeding  insects  that  you  know 
which  may  be  killed  by  internal  poisons. 

2.  Make  a  similar  list  of  those  that  may  be  killed  by  tracheal  poi- 
sons. 

3.  What  insects  in  your  locality  must  be  killed  by  the  use  of  noxious 
gases  ? 

4.  In  what  ways  have  you  seen  insecticides  applied? 

5.  Read  such  of  these  references  as  your  teacher  may  direct :  — 

Important  Insecticides,  Farmers'  Bulletin  127.  Carbon  Bisulphide  as  an  Insec- 
ticide, Farmers'  Bulletin  145.  Spraying  for  Orchard  Insects,  Yearbook  Reprint 
480. 


CHAPTER   XIII 
The  Predaceous  Insects 

WHILE  a  large  proportion  of  the  insects  that  we  meet  in 
our  walks  afield  are  in  one  way  or  another  injurious  to 
cultivated  crops  or  domestic  animals,  there  are  vast  num- 
bers of  species  which  may  be  regarded  as  either  beneficial 
or  neutral.  From  the  beginning  of  their  lives  as  eggs 
until  their  death  as  adults,  the  injurious  insects  are  beset 
by  a  multitude  of  enemies.  Some  of  their  enemies  attack 


TIGER  BEETLES 

them  with  wide-open  jaws,  devouring  the  victims  bodily, 
while  others  pierce  their  bodies  with  pointed  beaks  to  suck 
their  lifeblood.  Yet  others  insert  lancelike  ovipositors  by 
means  of  which  they  leave  inside  the  body  of  the  victim 
tiny  eggs  that  develop  into  parasites  whose  attacks  are  as 
fatal  as  those  of  the  larger  foes.  Those  insects  that  de- 
vour the  bodies  or  suck  the  lifeblood  of  their  victims  are 
called  Predaceous  Insects. 

There  are  a  great  many  different  groups  of  predaceous 
insects   belonging    to    many   families    in    various    orders. 

163 


164 


FARM   FRIENDS   AND   FARM   FOES 


There  is  room  in  these  pages  for  a  discussion  of  only  a  few 
of  the  more  important  of  these  groups. 

PREDACEOUS  BEETLES 

Among  the  notable  foes  of  injurious  insects  the  Pre- 
daceous  Ground  Beetles  (Carabidae)  hold  a  high  rank. 
They  are  active,  voracious  beetles,  having  hard,  flattened 
bodies,  strong  legs,  and  large  jaws.  They  hunt  commonly 
upon  the  ground  or  in  trees  and  shrubs  for  caterpillars  and 
other  insects  that  may  serve  as  food.  Cutworms,  army 
worms,  gypsy  moth  caterpillars,  and  similar  grass  and  leaf- 
feeding  larvae  are  especially  likely  to  be  caught  by  them. 


V 


GROUND  BEETLES 


Many  Ground  Beetles  are  black  in  color,  but  a  few  are 
greenish  blue,  and  some  are  marked  with  golden  spots. 
Specimens  are  nearly  always  to  be  found  beneath  boards 
or  logs  lying  loosely  on  the  soil  surface. 

The  larvae  of  most  of  these  ground  beetles  are  also  pre- 
daceous.  They  are  very  active,  and  are  provided  with 
large  jaws  for  catching  and  devouring  their  prey. 

The  Tiger  Beetles  (Cicindelidae)  are  perhaps  of  less 
economic  importance  than  the  Ground  Beetles  because  they 


THE   PREDACEOUS   INSECTS  165 

hunt  their  prey  in  a  more  restricted  range.  Tiger  Beetles 
are  to  be  found  in  open  sunny  spaces,  as  along  highways 
and  byways,  or  on  the  sandy  shores  of  lakes 
and  streams.  They  greedily  devour  such 
insects  as  they  find  in  their  eager  wander- 
ings. The  long  legs  are  fitted  for  rapid  run- 
ning ;  the  large  eyes  are  fitted  for  seeing  over 
a  wide  area;  the  strong  jaws  are  fitted  for 
sudden  grasping,  and  the  well-developed 
wings  are  fitted  for  quick  flight  on  the  approach  of  danger. 
The  wing-covers,  legs,  and  body  wall  are  very  hard  and 
often  brilliantly  colored  in  metallic  hues. 

In  early  life  the  Tiger  Beetles  are  curious  grublike 
larvae  that  live  in  burrows  in  hard  ground,  as  along  beaten 
paths  and  sandy  shores.  These  burrows  are  vertical  holes, 
nearly  as  large  as  the  diameter  of  a  lead  pencil.  The  larvae 
have  a  strangely  flattened  head  with  long,  widespread- 
ing  jaws.  Each  lies  in  wait  at  the  top  of  the  burrow, 
practically  invisible  on  the  smooth  surface  of  the  ground. 
When  an  unsuspecting  caterpillar  or  other  insect  passes 
over  the  waiting  head,  the  jaws  grasp  the  victim,  which  is 
quickly  dragged  into  the  burrow  to  be  devoured  at  leisure. 
From  an  economic  point  of  view  the  familiar  little  Lady- 
bird Beetles  (Coccinellidae)  are  perhaps 
the  most  important  of  all  the  predaceous 
beetles.  These  brightly  colored  little  crea- 
tures, in  both  their  larval  and  adult  stages, 
feed  chiefly  upon  the  destructive  aphides 
or  plant  lice,  destroying  every  year  billions 
of  the  pests. 

Wherever  you  find  a  colony  of  aphides 
sucking  the  sap  from  living  plants,  there  you  are  likely  to 
find  some  of  the  Ladybirds  at  work.  They  lay  their  eggs 


1 66  FARM  FRIENDS  AND   FARM   FOES 

on  leaves  or  stems,  the  eggs  of  the  larger  sorts  bearing  a 
general  resemblance  to  those  of  the  familiar  Colorado  po- 
tato beetle.  These  eggs  soon  hatch  into  the  curious  Lady- 
bird larvae  which  also  feed  upon  the  aphides,  destroying 
great  numbers  of  them.  After  some  weeks  of 
\\£v//  feeding,  the  Ladybird  larvae  attach  themselves  to 

\m/  leaf  or  bark  and  change  to  pupae,  soon  to  change 
Jflk  again  to  adult  beetles. 

/JIA         While  most  of  our  common  Ladybird  beetles 

J^P]  feed  chiefly  upon  aphides,  some  species  devour 
/  \  bark  lice.  One  of  the  most  noted  kinds  of 

BLISTER  beneficial  insects  is  the  celebrated  Australian 
Ladybird  —  Vedalia  cardinalis.  This  insect  was 
introduced  into  California  to  destroy  the  fluted  scale  —  a 
destructive  pest  in  orange  groves.  The  experiment  was 
quite  successful,  for  the  scale  insects  were  materially 
checked  by  their  little  foes. 

PREDACEOUS  BUGS 

Probably  the  most  important  predaceous  insects  in  the 
order  of  true  bugs  are  the  Soldier  Bugs  (Pentatomidae). 
These  belong  to  the  genus  Podisus  ; 
they  are  of  moderate  size,  the  larger 
common  ones  being  slightly  less  than 
an  inch  long,  with  flattened  bodies, 
well-developed  legs,  and  strong,  Sold 
sharply  pointed  beaks.  There  are  about  a  dozen  species, 
several  of  which  have  a  horizontal  spiny  projection  on  each 
side  of  the  back  behind  the  head. 

The  Spined  Soldier  Bug  is  one  of  the  largest  and  most 
widely  distributed  of  these  insects.  The  adults  pass  the 
winter  under  loose  bark,  fallen  trees,  loose  leaves,  or  other 
shelter.  In  spring  they  come  forth  and  attack  such  cater- 


THE  PREDACEOUS  INSECTS  167 

pillars  or  other  soft-bodied  insects  as  they  can  find,  sucking 
their  lifeblood  greedily.  They  lay  the  rather  large,  more 
or  less  barrel-shaped  eggs  in  clusters  upon  leaves  or  bark. 
The  eggs  soon  hatch  into  tiny  bugs  that  at  first  get  food 
by  sucking  the  sap  of  various  leaves  or  tender  stems. 

During  the  next  few  weeks  these  young  Soldier  Bugs 
molt  several  times,  increasing  in  size  each  time.  The 
time  when  they  stop  sucking  the  sap  of  plants  to  begin 
upon  the  blood  of  animals  seems  not  to  be  known,  but 
it  is  probably  when  they  are  about  half  grown.  During 
the  rest  of  their  lives  they  seem  to  prefer  animal  juices  to 
those  of  plants,  and  go  eagerly  about  in  search  of  victims. 
Among  the  most  important  of  these  are  the  larvae  of  the 
Colorado  potato  beetles,  asparagus  beetles,  cabbage  worms, 
web-worms,  tussock  caterpillars,  cotton  worms,  leaf  rollers, 
codling  moth  larvae,  sawfly  larvae,  and  even  the  curious 
walking  sticks. 

This  or  a  closely  related  Soldier  Bug  is  one  of  the  com- 
monest predaceous  enemies  of  the  tent  caterpillars,  occur- 
ring frequently  in  the  nest  of  the  American  tent  caterpillar. 

While  the  Soldier  Bugs,  as  befits  their  name,  are  bold 
freebooters,  constantly  invading  new  areas  in  search  of 
victims,  the  Ambush  Bugs  (Phymatidae)  have  quite  a  dif- 
ferent habit.  These  take  up  their  quarters  in  flowers  or 
other  shelter  where  they  patiently  lie  in  ambush  until  some 
unsuspecting  insect  comes  within  reach  of  their  curiously 
made,  grasping  arms.  As  soon  as  it  has  seized  the  victim, 
the  pointed  beak  serves  to  suck  out  the  body  juices,  and 
the  remains  are  cast  aside. 

Five  species  of  Ambush  Bugs  are  recorded  for  our  region. 
Only  one  of  these  is  so  abundant  and  widely  distributed  as 
to  be  generally  known.  It  may  be  called  Wolff's  Ambush 
Bug  and  is  in  color  a  curious  mixture  of  green  and  yellow. 


i68  FARM   FRIENDS  AND   FARM  FOES 

It  is  especially  likely  to  be  found  in  yellow  flowers,  waiting 
to  capture  unsuspecting  butterfly  visitors. 

The  Wheel  Bug  is  a  common  predaceous  insect  in  the 
Southern  states.  It  is  of  good  size,  being  more  than  an 
inch  long,  with  a  sharp  beak  and  a  curious  crest  on  the 
thorax  that  gives  it  its  common  name.  It  feeds  largely 
upon  caterpillars,  and  belongs  to  the  family  of  Assassin 
Bugs  (Reduviidae). 

TWO-WINGED  FLIES 

Of  the  great  number  of  families  of  two-winged  flies  com- 
paratively few  are  predaceous.  The  most  distinctive  of 
these  are  the  Robber  Flies  (Asilidae),  a  group  of  hawklike 
creatures,  some  of  which  may  often  be  seen  in  open  fields. 
Nearly  a  thousand  distinct  species 
are  found  in  North  America.  The 
more  familiar  forms  have  powerful 
wings  and  long  legs  and  abdomen. 
They  commonly  rest  on  low  shrubs 
or  plants  whence  they  can  readily 
pounce  upon  any  flying  insect  that 
passes  near.  Honeybees  are  so 
often  killed  by  them  that  in  some 
ROBBER  FLY  regions  these  flies  are  called  bee 

killers.    Such  victims  are  caught  by 

the  powerful  legs,  and  quickly  sucked  dry  by  the  voracious 
robbers.  A  few  species  bear  a  striking  resemblance  to 
bumblebees  and  wasps,  from  which  they  are  at  once  distin- 
guished by  having  but  one  pair  of  wings. 

So  far  as  their  earlier  stages  have  been  described,  the 
larvae  of  these  flies  seem  to  be  largely  predaceous  also. 
They  live  in  damp  soil  and  rotting  wood,  apparently  feeding 
upon  the  other  insects  found  in  such  situations. 


THE   PREDACEOUS   INSECTS  169 

A  colony  of  aphides  or  plant  lice  offers  many  oppor- 
tunities to  study  the  relations  of  various  groups  of  insects  to 
one  another.  In  such  a  colony  there  are  forms  of  winged 
and  wingless  aphides  as  well  as  several  kinds  of  enemies 
that  attack  them.  Among  the  latter  are  the  tiny  four- 
winged  parasites,  the  young  and  adult  ladybird  beetles,  and 
the  strange  Aphis  Lions.  In  addition  to  these,  you  can 
generally  find,  also,  a  curious  footless  grub  blunt  at  one  end 
and  sharply  pointed  at  the  other,  which  impales  the  plant 
lice  one  at  a  time  on  its  pointed  end,  sucks  the  lifeblood,  and 
casts  aside  the  empty  skins.  These  are  the  larvae  of  the 
Syrphus  Flies  (Syrphidae),  many  species  of  which  in  the 
larval  state  thus  prey  upon  the  aphides. 

The  Syrphus  Flies  are  generally  a  little  larger  than  the 
common  house  fly  and  may  be  found  in  abundance  visiting 
flowers  in  search  of  pollen  and  nectar.     The 
mother  flies  lay  their  elongated  whitish  eggs 
on  leaves  and  bark  amid  colonies  of  plant  lice. 
The  eggs  shortly  hatch  into  the  curious  larvae 
that  prey  upon  the  aphides.     When  full  grown, 
the  syrphid  larvae  change  to  pupae,  still  upon 
the  leaf  or  bark,  and  change  again  a  little  later  into  adult 
flies. 

FOUR-WINGED  FLIES 

The  great  order  of  Four-winged  Flies  —  Hymenoptera  — 
contains  several  families  that  may  be  classed  to  a  greater 
or  less  extent  in  the  predaceous  group.  One  of  the  most 
important  of  these  is  that  of  the  Ants,  which  are  so  univer- 
sally distributed  over  the  surface  of  the  earth.  Most  of  these 
ubiquitous  little  creatures  have  a  wide  range  of  food,  taking 
almost  anything,  living  or  dead.  There  is  no  doubt,  how- 
ever, that  they  are  important  foes  of  noxious  insects,  de- 


170  FARM  FRIENDS  AND   FARM  FOES 

stroying  unsuspected  numbers  of  eggs,  larvae,  and  later 
stages  of  plant-feeding  insects. 

The  Social  Wasps  (Vespidae)  are  well-known  predaceous 
insects.  The  adults  build  paper  nests  in  which  the  young 
are  reared,  being  fed  largely  with  various  insects  that  the 
worker  wasps  catch  for  them.  These  workers  also  feed 

freely  upon  such  insects,  though 
they  also  eat  the  nectar  of 
flowers  and  other  kinds  of  food. 
The  various  groups  of  Soli- 
tary Wasps  must  also  be  classed 
with  the  predaceous  insects, 
though  their  peculiar  habits 


HORET 

parasites.     The    Mud    Wasps 

and  the  Digger  Wasps  provision  their  cells  and  burrows  with 
flies,  grasshoppers,  caterpillars,  spiders,  and  other  crea- 
tures. These  victims  are  paralyzed  by  the  sting  of  the  wasp 
so  that  they  lie  helpless  in  the  cell  in  which  the  wasp  egg 
is  laid.  This  egg  soon  hatches  into  a  larva  that  feeds  upon 
the  paralyzed  prey,  finally  transforming  to  a  pupa  and  later 
to  an  adult  wasp. 

OTHER  ORDERS 

Comparatively  few  important  predaceous  families  are 
found  in  the  other  orders  of  insects.  Some  of  these,  how- 
ever, are  friendly  insects  of  great  value,  serving  a  notable 
purpose  in  the  economy  of  nature. 

What  the  swallows  are  among  the  birds,  the  Dragon  Flies 
are  among  the  insects.  These  powerful  creatures  are  won- 
derfully adapted  to  their  life  work.  With  enormous  eyes 
that  see  in  practically  all  directions,  with  powerful  wings 
that  carry  them  with  lightning  rapidity  through  the  air,  with 


THE  PREDACEOUS   INSECTS 


171 


DRAGON-FLY 


a  long  abdomen  that  serves  admirably  as  an  aerial  rudder, 
and  with  strong  front  legs  and  great  jaws  fitted  for  grasp- 
ing and  biting  their  victims,  they  may  in- 
deed appear  as  formidable  dragons  to  less 
fortunate  insects.  In  their  earlier  stages 
these  insects  develop  in  the  water,  where 
they  are  also  predaceous. 

The  Dragon  Flies  are  commonly  di- 
vided into  two  groups  :  those  in  which  the 
wings  are  held  vertically  when  the  insect 
is  at  rest  are  called  Damsel  Flies ;  those 
in  which  the  wings  are  held  horizontally 
when  the  insect  is  at  rest  are  called 
Dragon  Flies. 

Among  the  many  parasitic  and  predaceous  insects  to  be 
found  amid  colonies  of  plant  lice,  the  Aphis  Lions  are  per- 
haps the  most  remarkable.  These  are 
long-legged,  slender-bodied  creatures 
with  strange  long  jaws  between  which 
they  grasp  their  prey  while  they  suck 
the  body  dry.  They  are  the  larvae  of  the 
Golden-eyed  Lace-winged  Flies  (Chryso- 
pidas). 

The  curious  Mantids  of  the  order  Or- 
thoptera  are  also  remarkable  predaceous 
insects.     They  are  closely  related  to  the 
walking  sticks  and  lie  in  wait  till  vari- 
ous insects  come  within  reach  of  their 
grasping  front  legs.     The  native  Praying 
Mantis  is  not  uncommon  in   the  South- 
ern states,  while    another  species  from 
Europe  has  lately  been  introduced  into  New  York  state. 
There  are,  of  course,  many  predaceous  creatures  among 


EGG  MASS  OF 
MANTIS 


172  FARM   FRIENDS   AND   FARM   FOES 

the  spiders,  mites,  and  myriapods,  related  to  the  insects 
proper.  But  the  limitations  of  space  forbid  their  discus- 
sion here. 

OBSERVATIONS   FOR   PUPILS 
PREDACEOUS  BEETLES 

1.  If  you  can  find  any  of  the  Predaceous  Ground  Beetles,  keep  them 
alive  in  a  vivarium  for  a  few  days.     Furnish  cutworms,  cabbage  worms, 
or  other  caterpillars  for  food. 

2.  See  if  you  can  find  any  Tiger  Beetles  along  paths  and  roadsides. 
Which  way  do  the  beetles  face  when  they  alight  —  toward  you  or  not  ? 
Catch  two  in  an  insect  net.     Keep  them  in  a  vivarium  and  furnish 
caterpillars  for  food. 

3.  See  if  you  can  find  any  burrows  of  Tiger  Beetle  larvae  in  smooth- 
trodden  ground. 

4.  Bring  in  a  few  Ladybird  Beetles  and  keep  in  a  vivarium.     Furnish 
aphides  for  food.     See  if  you  can  find  any  Ladybird  larvae,  pupae,  or 
eggs. 

5.  For  a  fuller  account  of  Tiger   Beetles  read   Life  Histories  of 
American   Insects,  pages  19-27;  of  the  Ladybird  Beetles,  Stories  of 
Insect  Life,  Second  Series,  pages  49-55. 

PREDACEOUS  BUGS 

1 .  Look  in  tent  caterpillars'  nests  in  spring  to  see  if  you  can  find  any 
Soldier  Bugs.     Or  later  in  the  season  see  if  there  are  any  on  the  potato 
vines.     If  you  find  any,  keep  them  in  vivaria  for  a  few  days  and  see  the 
way  they  take  their  food. 

2.  In  summer  or  early   autumn  sweep  clusters   of  herbage  for  the 
yellowish  Ambush  Bugs.     Study  their  structure  to  see  the  sharp  beak 
and  the  curious  front  legs  fitted  for  grasping. 

3.  If  you  live  where  the  Wheel  Bugs  are  found,  keep  one  alive  and 
watch  it  feed  upon  caterpillars. 

4.  Read  the  life  story  of  the  Wheel  Bug  in  The  Insect  Book,  pages 
294-296. 

TWO-WINGED  FLIES 

i.  On  warm  days  look  for  the  Robber  Flies  along  sunny  roads. 
Listen  to  the  quick  buzz  as  they  fly  up  and  watch  how  they  lie  in  wait 
for  prey. 


THE  PREDACEOUS   INSECTS  173 

2.  Examine  a  colony  of  plant  lice  carefully.     Try  to  find  the  white 
eggs,  the  footless  larvae,  or  the  curious  brown  puparia  of  some  of  the 
Syrphus  Flies.     Watch  one  of  the  larvae  through  a  lens  to  see  the  way 
it  impales  its  victims. 

3.  Read  the  account  of  the  Robber  Flies  in  The  Insect  Book,  pages 
141-143 ;  of  the  Syrphus  Fly  in  Stories  of  Insect  Life,  First  Series, 
pages  50-51. 

ANTS  ANTD  WASPS 

1 .  Watch  the  surface  of  an  ant's  nest  to  see  if  any  insects  are  carried 
to  it. 

2.  Watch  wasps  and  hornets  as  they  fly  about  porches  and   near 
houses  to  see  if  they  catch  flies  and  other  insects. 

3.  Open  the  cells  of  a  Mud  Wasp's  nest  to  see  the  paralyzed  spiders 
or  caterpillars  inside. 

4.  Watch  the  places  where  Digger  Wasps  make  their  burrows  to 
see  the  insects  at  work. 

5 .  Read  such  of  the  following  accounts  of  the  life  histories  of  wasps 
as  you  have  access  to :  — 

The  Insect  Book,  pages  18-30.  American  Insects,  pages  490-510.  Nature  Biog- 
raphies, pages  102-106.  Life  Histories  of  American  Insects,  147-178.  Stories  of 
Insect  Life,  Second  Series,  pages  24-29,  or  the  book  by  Professor  and  Mrs.  Peck- 
ham,  entitled  The  Solitary  Wasps. 

OTHER  PREDACEOUS  INSECTS 

1 .  Watch  the  Dragon  Flies  and  Damsel  Flies  in  summer.     Notice 
the  position  of  the  wings  when  the  insects  alight. 

2.  Read  the  account  of  Dragon  Flies  in  American  Insects,  pages  75- 
89 ;  also  the  accounts  of  the  Praying  Mantis  in  The  Insect  Book,  pages 
326-328  ;  Stories  of  Insect  Life,  Second  Series,  pages  63-68. 


CHAPTER  XIV 


The  Four-winged  Parasites 

IT  is  fortunate  for  mankind  that  almost  all  species  of  in- 
jurious insects  have  insect  enemies  that  destroy  them. 
These  insect  enemies  are  divided  into  two  groups  as  regards 
the  methods  by  which  they  kill  their  victims.  There  is  no 
hard  and  fast  line  to  be  drawn  between  these  groups,  but 
in  general  we  may  safely  say  that  the  insects  which  destroy 
other  insects  are  either  parasites  or  predaceous  insects.  As 
a  rule,  the  parasites  develop  in  the  larval  state  within  the 
bodies  of  their  victims,  and,  as  a  rule,  the  predaceous  insects 
feed,  sometimes  during  the  earlier  stages,  sometimes  during 
their  adult  stage,  and  sometimes  during  both,  upon  their  vic- 
tims, attacking  them  from  the  out- 
side either  by  thrusting  a  pointed 
beak  through  the  skin  and  sucking 
their  lifeblood,  or  else  by  devouring 
them  bodily. 

THE  ICHNEUMON  FLIES 

One  of  the  most  important  groups 
of  parasitic  insects  is  that  of  the 
Ichneumon  Flies.  These  are  slen- 
der-bodied, more  or  less  wasplike 
creatures,  with  four  wings,  long 
antennae,  and  well-developed  legs 
You  may  very  often  see  them  run- 


ICHNEUMON   FLY  OVIPOS- 
ITING IN  COCOON 

adapted  for  running. 


ning  rapidly  over  the  surface  of  leaf  or  bark,  in  search 

174 


THE  FOUR-WINGED   PARASITES 


175 


of  victims  in  which  to  lay  their  eggs,  constantly  vibrating 
their  antennae.  Oc- 
casionally, also,  you 
may  see  them  visit- 
ing such  flowers  as 
have  the  nectar 
freely  exposed  to  lap- 
ping by  their  short 
tongues.  Or  you 
may  see  them  in  the 
evening  as  they  fly 
about  a  light  to 
which  they  are  at- 
tracted. 

The  Ichneumon 
Flies  vary  greatly 
in  size,  form,  and 
habits.  Some  are  so 
minute  as  to  be  barely 
visible  to  the  un- 
aided eye,  while 
others  measure  sev- 
eral inches  in  length, 
with  long  antennae 
and  slender  oviposi- 
tors extending  be- 
hind the  abdomen. 

Among  the  largest 
of  the  Ichneumon 
Flies  are  the  inter- 
esting brown  insects 
called  the  Ophion 
Flies.  The  life  his-  LONG-TAILED  ICHNEUMON  FLY 


i76 


FARM   FRIENDS   AND   FARM   FOES 


tory  of  one  of  these  in  brief  is  this  :  The  adult  fly  de- 
posits its  egg  within  the  body  of  a  caterpillar,  especially  the 
caterpillars  of  the  large  silkworm  moths,  like  the  polyphe- 
mus  moth  or  the  cecropia  moth.  This  egg  shortly  hatches 
into  a  small  white  footless  maggot  that  absorbs  the  body 
juices  of  the  host,  as  the  victim  is  often  called,  but  at  first 
does  not  seriously  interfere  with  its  development.  The 
caterpillar  with  its  enemy  inside  continues  to  feed  and  grow 
for  some  time.  It  is  commonly  able  to  spin  its  cocoon  and 
perhaps  change  to  a  pupa  within  the  cocoon  before  the 
larva  of  the  parasite  becomes  so  large  as  to  kill  the  host. 
It  does  kill  it,  however,  finally,  and  then  within  the  protect- 
ing shelter  of  the  host's  cocoon, 
the  larva  of  the  Ophion  Fly 
changes  to  a  chrysalis.  The  fol- 
lowing spring  it  will  change  again 
to  an  adult  fly,  like  the  one  that 
laid  the  egg  in  the  caterpillar  so 
many  months  before.  This  fly 
is  provided  with  sharp  jaws  by 
means  of  which  it  gnaws  its  way 
out  of  the  cocoon  and  flies  freely 
about.  It  has  thus  completed 
the  cycle  of  a  parasite's  life. 

Sometimes  the  egg  of  the  par- 
asite is  not  laid  within  the  cater- 
pillar until  after  it  has  spun  its 
cocoon.  This  is  often  the  case 
with  certain  medium-sized  Ich- 
neumon Flies  of  the  genus 
Pimpla.  These  may  sometimes  be  seen  standing  upon  the 
cocoons  of  the  common  apple-tree  tent  caterpillar,  with  the 
ovipositor  thrust  down  through  the  cocoon  in  the  manner 


ICHNEUMON  FLY  AND  BUTTER- 
FLY CHRYSALIS  IN  WHICH  IT 
DEVELOPED 


THE   FOUR-WINGED   PARASITES  177 

illustrated  on  page  174.  The  egg  develops  within  the 
body  of  the  host  into  a  white  footless  maggot  that  soon 
matures  as  a  larva  and  changes  to  a  pupa,  which  in  turn 
shortly  changes  into  an  adult  Pimpla. 

Many  of  the  Ichneumon  Flies  deposit  their  eggs  within 
the  burrows  of  larvae  that  bore  in  the  stems  of  herbaceous 
plants  or  the  bark  or  trunks  of  shrubs  and  trees.  In  such 
cases,  it  evidently  would  be  difficult  for  the  mother  parasite 
to  find  precisely  the  location  of  the  burrowing  larva,  so  she 
simply  deposits  her  egg  within  the  burrow  of  the  latter, 
and  the  little  larva  that  hatches  from  this  egg  is  generally 
provided  with  some  method 
by  which  it  is  able  to  reach 
its  victim.  Instead,  however, 
of  developing  on  the  inside 
of  its  host,  it  usually  simply 
attaches  itself  to  the  skin  and 

sucks  its  lifeblood  from  the  outside.  It  finally  kills  the 
host,  becomes  full-grown  as  an  Ichneumon  larva,  and  changes 
first  to  a  pupa,  and  a  little  later  into  an  adult  fly  that  is  able 
to  eat  its  way  out  through  the  bark  of  the  plant. 

MlCROGASTER   FLIES 

One  of  the  most  abundant  groups  of  the  Ichneumon 
Flies  is  that  of  the  Microgaster  Flies.     These  are  rather 

small  insects  that  deposit  their 
eggs  in  smooth-skinned  caterpil- 
lars of  many  kinds.  As  a  rule, 
COCOONS  OF  MICROGASTER  each  female  fly  is  provided  with 
a  pointed  ovipositor  with  which 

she  can  pierce  the  skin  of  the  caterpillar  to  insert  her  eggs 
within  its  body.  These  eggs  shortly  hatch  into  tiny  mag- 
gots that  develop  at  the  expense  of  the  tissues  of  the  un- 


i78 


FARM   FRIENDS  AND   FARM   FOES 


fortunate  host.     In  a  few  weeks  the  maggots  become  full- 
grown,  and  then  each  burrows  its  way  out  through  the  skin 

of  the  victim.  Once  outside, 
each  maggot  spins  some  sort  of 
silken  cocoon  within  which  it 
changes  first  to  a  pupa,  and 
later  to  an  adult  Microgaster 
similar  to  the  one  that  laid  the 
eggs. 

There  is  much  variation  in 
the  color,  form,  and  arrange- 
ment of  the  cocoons  of  these 
Microgaster  Flies.  Some  are 
white,  others  yellow.  Some  are 
formed  singly,  others  side  by 
side  in  a  compact  mass,  and  still 
others  in  a  loose  mass  of  fluffy 
silk. 

There  is  also  great  variation 
in  the  number  of  parasites  to  a  single  caterpillar.  Some- 
times there  is  but  one  parasite  to  a  host,  as  in  the  case  of 
certain  leaf  miners,  sometimes  there  are  only  a  few,  but 
more  commonly  there  are  a  great  many  —  several  hundred 
in  the  case  of  the  tomato  worm  and  other  sphinx  cater- 
pillars. 

PLANT-LOUSE  PARASITES 

Almost  any  colony  of  plant  lice  will  furnish  examples  of 
the  extremely  interesting  family  of  tiny  flies  that  prey 
especially  upon  the  aphides.  These  are  little  four-winged 
flies  so  small  as  to  be  barely  visible  to  the  unaided  eye, 
which  develop  in  their  younger  stages  in  the  bodies  of  the 
plant  lice,  and  cause  the  death  of  untold  billions  of  these 
vexatious  pests. 


CATERPILLAR  WITH  COCOON 
MASS  OF  MICROGASTER  PARA- 
SITES 


THE  FOUR-WINGED   PARASITES 


179 


PARASITE 
of 

GRAIN   APHIS 


MAGNIFIED 


Aphis  Killed  by 
parasite 


A  considerable  proportion  of  these  tiny  parasites  belong 
to  the  genus  Aphidius.  The  fly  generally  deposits  her  egg 
within  the  abdo-  .,  ' 
men  of  the  aphid. 
The  egg  shortly 
hatches  into  a 
tiny  footless 
maggot  that  lives 

within  the  body    _    y™  _         ,^  AphiS  with  parade 

of    its    host,    ab-  /  JBL^^  larva  inside 

sorbing  the  ma- 
terials of  growth 
from  it,  and  often 
being  visible 
while  the  host  in- 
sect apparently 
is  still  alive.  Fi- 
nally the  parasite  larva  becomes  fully  developed,  absorb- 
ing practically  all  the  contents  of  the  aphid's  body,  kill- 
ing it,  and  leaving  only  the  inflated  skin  of  the  latter  to  serve 
as  a  protection  to  the  parasite.  Within  this  brown  inflated 
skin,  the  larval  parasite  changes  to  a  pupa  and  very  soon 
afterward  changes  again  to  a  tiny  fly,  resembling  the  one 
that  laid  the  egg.  This  fly  gnaws  out  a  circular  piece  in 
the  skin  of  the  dead  host,  making  a  hole  through  which 
it  emerges  to  continue  the  good  work  of  aphis  destruction. 

Very  often  these  little  parasites  are  important  means  of 
checking  outbreaks  of  destructive  aphides.  The  parasite 
of  the  grain  aphis,  illustrated  herewith,  is  a  notable  example 
of  this.  Under  certain  conditions  which  are  favorable  to 
the  development  of  the  plant  louse,  but  not  favorable  to  the 
development  of  the  parasite,  the  former  become  exceedingly 
destructive  in  the  grain  fields  of  the  South  and  West. 


i8o  FARM   FRIENDS  AND   FARM   FOES 

Under  ordinary  conditions,  however,  this  pest  seems  to  be 
held  in  check  to  a  great  extent  by  the  tiny  fly  that  develops 
in  enormous  numbers  at  its  expense. 

PRIMARY  AND  SECONDARY  PARASITES 

The  ichneumon  flies  discussed  in  the  previous  pages  de- 
velop as  parasites  of  various  plant-feeding  caterpillars. 
They  are  known  as  primary  parasites. 

It  very  commonly  happens,  however,  that  these  primary 
parasite  larvae  are  themselves  attacked  by  other  ichneumon 
fly  larvae  that  attach  themselves  to  the  former  and  suck 
their  lifeblood.  Such  parasites  of  parasites  are  said  to  be 
secondary  parasites. 

It  also  happens  sometimes  that  one  of  these  secondary 
parasites  is  in  turn  attacked  by  a  third  larva  that  sucks  out 
its  lifeblood.  Such  parasites  of  parasites  of  parasites  are 
said  to  be  tertiary  parasites. 

Perhaps  you  will  be  able  to  remember  these  facts  better 
if  I  quote  a  famous  old  rhyme  :  — 

The  little  fleas  that  do  us  tease, 

Have  other  fleas  that  bite  'em, 
And  these  in  turn  have  other  fleas 

And  so  ad  infinitum. 

In  general  these  parasites  of  parasites  are  spoken  of  as 
hyperparasites. 

Attention  has  recently  been  called  by  W.  F.  Fiske  to  an- 
other important  phase  of  parasitism.  It  very  commonly 
happens  that  two  or  even  more  primary  parasites  attack 
the  same  caterpillar.  One  of  these  may  devour  the  avail- 
able food  so  rapidly  that  the  other  will  die.  Or  they  may 
both  become  fully  developed,  but  be  so  dwarfed  from  the 
limited  food  supply  that  they  are  unable  to  lay  eggs  for  an- 


THE  FOUR-WINGED   PARASITES  181 

other  brood  of  parasites.     Or  they  both  may  die  from  lack 
of  food. 

Mr.  Fiske  has  applied  the  term  superparasitism  to  this 
excessive  parasitism  of  primary  hosts.  He  classifies  the 
various  conditions  that  may  exist  as  follows :  — 

I.    One  parasite  lives  ;  the  other  dies. 

(a)  The  survivor  preys  upon  the  other  as  an  acci- 
dental secondary  parasite.     Of  common  occur- 
rence. 

(b)  The  survivor  destroys  the  other  by  bringing 
about  the  premature  death  of  the  host  and  may 
or  may  not  devour  it  incidentally.     Of  common 
occurrence. 

II.    Both  parasites  live. 

(c)  Neither   is   the   worse  for  the  circumstances. 
Very  rare. 

(d)  One  or  both  are  so  seriously  weakened  and 
stunted  as  to  bring  about  a  material  reduction 
in  their  capacity  for  reproduction.     Common. 

III.    Neither  parasite  survives. 

(i)  This  may  be  brought  about  through  the  prema- 
ture death  of  the  host  through  excessive  para- 
sitism (commonly) ;  or 

(/)  Through  the  inability  of  either  parasite  to 
complete  its  transformations  on  the  limited 
supply  of  food.  Common. 

If  you  will  stop  to  think  what  must  be  constantly  hap- 
pening in  the  world  of  insects  on  account  of  the  existence 
of  these  many  primary,  secondary,  and  other  parasites,  you 
will  see  that  the  relations  between  them  must  be  very  com- 
plicated. A  caterpillar  that  is  a  great  crop  pest  becomes 
abundant.  Its  primary  parasites  soon  become  abundant 


182  FARM  FRIENDS  AND  FARM  FOES 

also,  because  they  can  multiply  rapidly  when  their  caterpil- 
lar hosts  are  numerous.  And  so  they  tend  to  check  the 
caterpillar  outbreak.  But  when  the  primary  parasite  is 
abundant,  the  secondary  parasite  can  also  multiply  rapidly. 
So  these  will  tend  to  check  the  numbers  of  the  primary 
parasite  and  thus  relieve,  so  to  speak,  the  pressure  upon  the 
caterpillars.  The  case  will  also  be  complicated  by  the 
many  examples  of  superparasitism.  Consequently  there  is 
a  constant  fluctuation  in  the  numbers  of  these  different  in- 
sects—  each  one  now  abundant,  then  scarce  —  with  a  ten- 
dency toward  a  normal  level.  This  complicated  condition 
is  often  spoken  of  as  the  Balance  of  Nature. 

THE   CHALCID  FLIES 

The  ichneumon  flies  are  not  the  only  important  group  of 
four-winged  parasites.  From  an  economic  point  of  view 
the  great  family  of  Chalcid  Flies  is  perhaps  of  as  great 
value,  although  on  account  of  their  smaller  size  they  are 
not  so  well  known.  It  is  believed,  however,  by  Dr.  L.  O. 
Howard,  our  foremost  authority  upon  these  insects,  that 
there  are  more  species  in  this  family  than  in  any  other  of 
the  great  order  of  four-winged  flies. 

The  Chalcids  are  very  small  four-winged  flies  that  develop 
in  the  earlier  stages  of  other  insects.  They  are  especially 
likely  to  infest  the  eggs  and  larvae  of  butterflies,  moths, 
beetles,  and  sawflies,  as  well  as  the  larvae  of  great  numbers 
of  two  and  four-winged  gallflies,  ichneumon  flies,  wasps,  bees, 
and  two-winged  flies.  They  are  also  very  destructive  to 
scale  insects  and  sometimes  develop  in  plant  lice  and  other 
families  of  true  bugs,  as  well  as  in  the  eggs  of  tree  crickets 
and  other  members  of  the  order  Orthoptera. 

In  the  case  of  many  Chalcid  Flies  the  life  history  seems 
to  be  as  simple  as  in  that  of  the  more  familiar  ichneumons. 


THE  FOUR-WINGED   PARASITES  183 

The  mother  insect  deposits  one  or  more  eggs  in  a  caterpil- 
lar. The  eggs  hatch  into  tiny  maggots.  The  maggots 
grow  inside  the  body  of  the  host,  absorbing  its  substance. 
They  finally  change  to  pupae,  generally  within  the  body  of 
the  dead  or  dying  host,  to  emerge  later  as  fully  developed 
Chalcid  Flies. 

Many  of  the  Chalcids  are  parasites  of  borers,  gallflies, 
and  leaf  miners.  As  a  rule,  the  larvae  in  such  cases  develop 
as  external  parasites  upon  their  victims.  You  may  often 
find  examples  of  these  if  you  will  examine  a  number  of 
leaf -miner  cavities.  Many  other  Chalcids  are  parasites 
upon  the  larvae  of  the  ichneumon  flies — that  is,  they  are 
secondary  parasites.  In  such  cases,  also,  the  Chalcid  larvae 
generally  develop  as  e  -ternal  feeders  upon  the  ichneumon- 
fly  larvae. 

A  considerable  number  of  the  Chalcid  Flies,  however, 
have  lives  that  cannot  be  told  in  the  few  words  that  will 
give  the  life  history  of  the  others.  They  go  through  so 
wonderful  a  course  of  development  that  it  has  required  the 
most  careful  studies  of  many  scientists  for  years  to  trace  it 
out.  Even  now  we  know  but  little,  and  that  only  in  re- 
lation to  a  very  few  species.  But  what  we  do  know  enables 
us  to  explain  certain  facts  which  before  were  very  puzzling. 

If  you  will  bring  in  a  lot  of  nearly  full-grown  larvae  of 
the  Cabbage  Plusia  and  keep  them  in  a  vivarium,  a  good 
many  of  them  will  be  likely  to  die  because  they  are  in- 
fested with  parasites.  If  you  will  isolate  those  that  die, 
keeping  them  in  small  bottles  or  boxes  so  you  can  see  how 
many  parasites  come  from  each  caterpillar,  you  will  prob- 
ably find  that  from  some  there  emerge  hundreds  if  not 
thousands  of  tiny  four-winged  Chalcid  Flies.  In  one  case 
three  thousand  such  flies  were  counted  from  one  cater- 
pillar. 


184  FARM  FRIENDS  AND   FARM  FOES 

If  you  stop  to  think,  you  can  scarcely  fail  to  wonder 
how  it  was  possible  for  one  or  even  several  mother  flies 
to  lay  so  many  eggs  in  a  single  caterpillar.  Indeed,  it  has 
been  found  that  one  fly  probably  cannot  lay  more  than  one 
or  two  hundred  eggs,  and  it  would  seem  hard  to  believe 

that  a  dozen  or  more  of 
these  flies  laid  their  eggs 
upon  the  Plusia  caterpil- 
lar all  at  once.  But  if 
they  did  not  do  this,  how 
may  we  account  for  the 
three  thousand  parasites  ? 
CHALCID" PARASITE  OF  GYPSY  MOTH  The  observations  of  sev- 

EGGS  eral  European  entomolo- 

gists indicate  that  the  life 
story  of  these  parasites  is  something  like  this :  — 

The  Plusia  Moth  lays  its  egg  upon  the  cabbage  leaf. 
Shortly  afterward  the  Chalcid  Fly  lays  its  egg  within  the 
egg  of  the  Plusia  Moth. 

The  Chalcid  egg  remains  within  the  Plusia  egg,  so  that 
the  latter  hatches  into  a  caterpillar  with  the  unhatched 
.Chalcid  egg  within  its  body. 

After  a  time  the  Chalcid  egg  hatches,  but  not  into  a 
single  larva.  By  a  wonderful  process  its  contents  develop 
into  hundreds  of  tiny  larvae  that  live  on  the  body  substance 
of  the  Plusia  caterpillar.  They  grow  gradually  inside 
their  caterpillar  host.  The  latter  finally  dies,  and  the  thou- 
sands of  parasites  change  to  pupae  within  the  skin.  A 
little  later  they  change  to  flies. 

So,  instead  of  the  original  egg  developing  into  one  Chal- 
cid Fly  as  is  so  often  the  case,  it  develops  into  hundreds 
if  not  thousands.  Suppose  a  female  Chalcid  Fly  laid  an 
egg  in  each  of  a  hundred  Plusia  caterpillars,  and  each  egg 


THE  FOUR-WINGED   PARASITES  185 

developed  into  a  thousand  flies.     Of  how  many  flies  would 
she  be  the  mother  ? 

Do  you  wonder  that  these  parasites  are  important  ene- 
mies of  injurious  insects,  and  are  often  able  to  check  seri- 
ous outbreaks  of  great  crop  pests  ? 


THE  PROCTOTRYPID  FLIES 

The  third  great  group  of  insect  parasites  is  that  of  the 
Proctotrypid  Flies.  These  are  nearly  all  very  minute  crea- 
tures somewhat  similar  to  the  chalcid  flies.  A  large  pro- 
portion of  them  develop  in  the  eggs  of  other  insects,  sev- 
eral sometimes  emerging  from  a  single  host  egg.  Many 
of  them  are  parasites  upon  parasites,  and  some  undergo  a 
development  of  many  larvae  from  one  egg,  as  in  the  case 
of  some  of  the  chalcids. 

There  is  one  giant  in  this  family.  It  is  the  strange 
Pelecinus  Fly  pictured  below.  Apparently  it  is  a  parasite 
of  the  white  grub  —  the  larva  of  the  common  May  beetle. 
The  female  Pelecinus  is  much  smaller  than  the  male  and 
is  a  very  different-looking  insect 


PELECINUS  FLY 


186  FARM   FRIENDS  AND   FARM  FOES 

OBSERVATIONS   FOR   PUPILS 

AMERICAN  TENT  CATERPILLAR 

1 .  Collect  a  few  nearly  full-grown  caterpillars  from  the  nests  late  in 
spring  and  keep  in  vivaria,  feeding  as  necessary.     See  how  many  of 
them  are  killed  by  parasites. 

2.  Collect  from  the  nests  any  cocoons  that  may  be  made  in  them. 
These  are  pretty  sure  to  be  infested  by  parasites.     See  how  many  sorts 
of  flies  come  from  them. 

3.  See  if  you  can  find  in  the  nests  peculiar  shrunken  caterpillar  skins 
with  a  cocoon  inside.     Keep  these  and  rear  the  parasites. 

4.  Look  up  these  references  :  — 

Stories  of  Insect  Life,  First  Series,  pages  10-11.    Nature  Biographies,  pages  22-34. 

CABBAGE  BUTTERFLY 

1.  Early  in  spring  look  on  boards,  fences,  or  the  sides  of  build- 
ings near  gardens  where  cabbages  have  been  planted,  for  masses  of  the 
small  yellow  cocoons  of  microgaster  parasites.     Keep  such  cocoons  in 
closed  vials  or  boxes  to  rear  the  flies.     If  two  kinds  of  flies  emerge,  the 
larger  black  ones  will  be  the  microgaster  flies,  which  are  the  primary 
parasites,  and  the  smaller  flies  will  be  secondary  parasites. 

2.  Early  in  spring  collect  a  number  of  the  cabbage  butterfly  chrysalids 
that  may  be  found  in  boards  and  fences  near  old  cabbage  patches. 
Keep  in  small  vivaria.     From  some  of  them  you  will  be  likely  to  rear 
hundreds  if  not  thousands  of  small  chalcid  flies.     Count  the  number 
from  one  chrysalis.     Let  the  flies  escape  to  continue  their  good  work. 

3.  In  autumn  collect  a  number  of  cabbage  worms.     They  may  gen- 
erally be  found  abundantly  on  cabbages.     Keep  them  in  vivaria.     See 
how  many  are  killed  by  parasites. 

4.  Read  The  Insect  Book,  pages  57-60  ;  Stories  of  Insect  Life,  First 
Series,  pages  16-17. 

FALL  WEB-WORM 

1.  Early  in  autumn  collect  a  score  or  more  nearly  full-grown  fall 
web-worms  and  place  in  vivaria.     Several  of  them  are  likely  to  be  killed 
by  parasites. 

2.  Find  cocoons  of  the  fall  web-worm  in  which  external  parasites  are 
preying  on  the  larvae. 

3.  Read  The  Insect  Book,  pages  64-68. 


THE  FOUR-WINGED   PARASITES  187 

APHIDES  OR  PLANT  LICE 

1.  Find  some   colonies  of  aphides  on  some  shrub,  tree,  or  herb. 
They  are  commonly  abundant  on  cabbage  leaves.     Look  carefully  for 
brown  inflated  specimens.     These  are  parasitized. 

2.  Place  some  of  these  parasitized  aphides  in  small  vials  and  rear 
the  adult  parasitic  fly.     Notice  the  hole  through  which  it  comes. 

3.  Read  Life  Histories  of  American  Insects,  pages  197-199. 

SPHINX  CATERPILLARS 

1.  Look  over  tomato  vines,  grapevines,  Virginia  creeper,  and  other 
plants  to  see  if  you  can  find  any  large  sphinx  caterpillars  bearing  on 
their  backs  the  cocoons  of  microgaster  flies.     If  you  find  any,  place  each 
in  a  vivarium. 

2.  Notice  whether  the  parasitized  caterpillar  eats  and  how  long  it 
lives.     When  the  flies  emerge,  notice  whether  they  are  all  the  black 
microgasters  which  are  the  primary  parasites  or  whether  there  are  some 
bright-colored  chalcid  flies,  which  are  secondary  parasites. 

3.  Read  these  references  :  — 

Life  Histories  of  American  Insects,  pages  181-188.     Nature  Biographies,  pages 
122-131. 


CHAPTER   XV 
The  Two-winged  Parasites 

IN  the  great  order  of  two-winged  flies  (Diptera)  there 
are  many  parasites  of  other  insects.  A  large  proportion  of 
these  belong  to  the  family  of  Tachina  Flies  (Tachini- 
dae).  These  are  mostly  insects  of  moderate  size,  similar 
in  appearance  to  the  common  house  fly  but  usually  some- 
what larger. 

These  Tachina  parasites  have  long  been  recognized  as 
among  the  most  important  enemies  of  such  smooth-skinned 

caterpillars  as  cutworms 
and  army  worms,  often 
destroying  millions  of 


these  pests  at  the  time 
of    a    single     outbreak. 
TACHINID  of  ARMY-WORM  The  life  history  as  shown 

by  the  species  that  in- 
fests the  army  worm  is  briefly  this  :  The  adult  flies  de- 
posit their  oval  whitish  eggs  upon  the  outside  of  the  skin 
of  the  caterpillar.  These  eggs  shortly  hatch  into  tiny 
larvae  by  burrowing  through  the  eggshell  and  also  through 
the  skin  of  the  caterpillar,  finding  lodgment  among  the 
body  tissues.  Here  they  rapidly  develop  into  whitish  foot- 
less maggots  that  finally  kill  the  host  and  emerge  to  change 
to  the  pupa  state  at  or  near  the  surface  of  the  soil.  They 
soon  again  change  to  adult  flies  to  continue  the  generation 
of  the  parasite. 

188 


THE  TWO-WINGED   PARASITES  189 

VARIATIONS  IN  LIFE  HISTORIES 

Until  recently  the  life  histories  of  the  other  Tachina 
Flies  have  been  supposed  to  be  similar  to  the  development 
of  that  preying  upon  the  army  worm.  But  the  careful 
studies  of  Dr.  C.  H.  T.  Townsend  upon  the  parasites  of  the 
gypsy  and  the  brown-tail  moths  show  a  marvelous  variation 
in  the  life  histories  of  these  flies,  and  establish  their  great 
value  as  enemies  of  hairy  caterpillars  as  well  as  of  those 
with  smooth  skins.  Dr.  Townsend  found  that  at  least  one 
of  the  flies  that  preys  upon  the  brown-tail  moth  deposits 
eggs  upon  the  young  caterpillars,  the  eggs  hatching  and 
penetrating  the  skins  of  the  caterpillars,  much  as  in  the 
case  of  the  parasite  that  kills  the  army  worm.  But  the 
other  Tachinid  parasites  had  surprisingly  different  life  his- 
tories, the  discovery  of  which  required  months  of  patient 
observation. 

Several  species  of  these  flies  deposit  their  small  eggs  upon 
the  leaves  where  the  caterpillars  are  feeding,  the  eggs  be- 
ing often  fastened  to  the  freshly  eaten  edge  of  the  leaf. 
The  eggs  are  swallowed  by  the  caterpillar  with  the  leaf 
particles,  generally  escaping  injury  from  the  jaws  because 
they  are  so  minute.  Soon  after  being  swallowed,  the  eggs 
hatch  into  tiny  maggots  that  burrow  through  the  wall  of 
the  alimentary  canal  into  the  general  body  cavity  of  the 
host.  Here  they  absorb  food  and  grow,  finally  changing 
to  pupae  and  again  to  adult  Tachina  Flies  —  meanwhile 
causing  the  death  of  the  caterpillar. 

These  observations  upon  the  leaf  laying  of  the  Tachinid 
eggs  indicated  an  unsuspected  ability  on  the  part  of  the 
flies  to  overcome  difficulties.  Evidently  the  hairy  clothing 
of  the  caterpillars  would  prove  of  no  value  as  a  protection 
from  parasites  if  the  very  food  is  laden  with  the  eggs  of 


i  go 


FARM  FRIENDS  AND   FARM  FOES 


the  enemy.     But  the  next  species  to  be  studied  revealed  a 
still  different  method  of  reaching  the  interior  of  the  host. 

Observations  upon  the  development  of  the  Tachinid  eggs 
indicated  the  probability  that  some  kinds  of  these  flies  would 
deposit  living  larvae  instead  of  eggs.  Two  species  were 
especially  studied,  and  it  was  found  that  the  flies  were  fur- 
nished with  "  a  long  curved  sheath,  into  the  base  of  which 
the  ovipositor  fits,  and  which  tapers  to  a  microscopically 
sharp  point."  By  means  of  this 
instrument  the  flies  are  able  to 
thrust  the  sheath  between  the  hairs 
of  the  caterpillar,  cut  a  hole  in  the 
skin,  and  insert  the  living  larva  in- 
side the  body  of  the  victim.  From 
the  point  of  view  of  the  parasite 
this  method  has  obvious  advan- 
tages :  the  young  larva  is  placed 
amid  favorable  surroundings  at  once 
with  no  danger  that  it  will  find  itself 
attached  to  a  molted  caterpillar  skin. 
And  the  interesting  fact  was  brought  out  that  various  na- 
tive flies  have  a  similar  sheath  and  doubtless  a  similar  life 
history. 

A  REMARKABLE  LIFE  HISTORY 

It  is  not  strange  that  Dr.  Townsend  found  a  species  that 
we  may  for  convenience  call  the  Large-horned  Tachina  Fly, 
the  "  most  remarkable  as  regards  startling  deviations  from 
the  previously  known  manner  of  reproduction"  in  the 
group.  It  was  at  first  supposed  that  these  flies  would 
deposit  their  eggs  upon  the  skins-  of  caterpillars  in  the 
old-fashioned  way.  To  a  female  fly  having  this  habit,  the 
presence  of  a  good-sized  gypsy  or  brown-tail  caterpillar 


TACHINA  PARASITE  OF 

GYPSY  MOTH 

Magnified 


THE  TWO-WINGED   PARASITES  191 

should  be  welcomed  as  an  opportuhity  for  depositing  an 
egg  and  thus  fulfilling  the  chief  purpose  of  her  existence. 
Consequently  the  investigators  were  puzzled  to  find  that 
these  flies  not  only  did  not  so  deposit  their  eggs,  but  were 
actually  alarmed  by  the  presence  of  the  caterpillars. 

It  was  easily  learned  through  the  study  of  dead  flies  that 
the  eggs  were  large  elongated  objects,  too  large  to  be  swal- 
lowed safely  by  the  intended  victims,  —  safely,  that  is,  for 
the  parasite.  Hence  it  could  not  be  that  they  were  laid 
upon  the  leaves  to  be  eaten.  If  they  were  not  to  be  de- 
posited on  or  in  the  caterpillars  and  were  not  to  reach  the 
interior  of  their  hosts  by  being  eaten,  how  was  it  to  be 
done  ? 

The  final  solution  may  well  be  given  in  Dr.  Townsend's 
own  words  :  "  After  much  patient  observation  and  experi- 
ment this  question  was  answered.  The  flies  were  found  to 
deposit  living  maggots,  not  on  or  in  the  caterpillars,  but, 
most  remarkable  to  relate,  on  the  green  shoots,  leaf  stems, 
leaf  ribs,  and  even  sometimes  on  the  surface  of  the  leaves." 
This  was  not  a  matter  of  chance,  however,  for  the  flies 
hovered  in  the  air  above  the  leaves  where  the  caterpillars 
were  at  work,  evidently  seeking  for  favorable  places  for 
depositing  the  larvae.  By  some  sense  —  perhaps  sight,  per- 
haps smell,  possibly  both  —  they  knew  when  the  caterpil- 
lars were  present  and  could  not  be  induced  to  deposit  on 
branches  where  they  were  not  present  or  had  not  been 
crawling. 

In  crawling  along,  many  of  these  caterpillars  of  the  great 
group  of  silk  spinners  have  an  interesting  habit  of  marking 
their  trail  by  a  silken  thread  which  is  continually  spun  from 
the  silk  glands  in  the  mouth  as  the  larva  marches  to  its 
feeding  grounds.  This  thread  serves  to  guide  it  back  to 
its  permanent  or  temporary  quarters  when  its  meal  is  fin- 


192  FARM   FRIENDS   AND   FARM   FOES 

ished.  If  you  will  look  at  a  nest  of  our  native  tent  cater- 
pillars in  spring,  you  will  see  silken  webs  leading  from  the 
tents  in  all  directions.  These  are  made  by  the  individual 
caterpillars  on  their  daily  journeys  in  and  out. 

It  is  evident  that  the  Tachina  Fly  knows  about  this  trail 
of  the  silk-spinning  caterpillar.  And  apparently  she  can 
tell  whether  it  is  a  fresh  trail  on  which  the  caterpillar  has 
gone  out  and  not  returned,  or  an  old  one  which  would  be 
comparatively  useless  for  her  purpose.  "  Doubtless,"  writes 
Dr.  Townsend,  "the  flies  larviposit  only  on  freshly  laid 
strands  which  have  not  lost  the  odor  of  the  caterpillar." 
Upon  this  fresh  strand  of  silk  she  deposits  a  living  larva 
that  is  wonderfully  adapted  to  making  its  way  in  the  world. 
On  the  hind  end  of  its  body  there  is  a  curious  sucker-like, 
membranous,  cup-shaped  case,  by  means  of  which  the  tiny 
maggot  is  fastened  to  the  leaf  on  or  near  the  silken  thread. 
On  the  front  end  of  its  body  is  a  slightly  sickle-shaped  hook, 
admirably  designed  for  rending  the  skin  of  the  caterpillar. 
Thus  it  is  anchored  in  the  path  of  its  prospective  victim 
with  its  stiletto  ready  for  business  at  a  moment's  notice. 
As  long  as  all  is  quiet,  it  lies  lazily  down,  but  on  any  dis- 
turbance, such  as  would  be  made  by  the  homeward  return 
of  the  caterpillar,  our  young  pirate  becomes  active  and 
ready  to  fasten  upon  the  expected  caterpillar. 

If  you  will  examine  a  good-sized  web-worm  or  gypsy 
moth  caterpillar  you  will  find  that  it  is  well  protected  by  its 
hairy  covering  along  its  back  and  sides.  But  on  the  lower 
surface,  the  skin  is  more  exposed,  and  it  is  obvious  that  this 
Tachinid  larva  lying  in  wait  with  its  stiletto  will  find  the 
caterpillar  as  it  crawls  above  it  an  easy  victim  for  its  hook. 
When  the  mouth  hook  is  thrust  through  the  skin,  the  pull 
of  the  caterpillar  loosens  the  hold  of  the  parasite  upon  the 
membranous  case  at  the  hind  end  of  its  body  and  the  par- 


THE  TWO-WINGED   PARASITES  193 

asite  remains  with  its  host,  working  its  way  through  the 
skin  to  the  inside  and  there  remaining  until  it  reaches  its 
full  development  into  the  adult  fly,  at  the  expense  of  the 
life  of  its  caterpillar  victim. 

OBSERVATIONS  FOR  PUPILS 

1 .  Examine  carefully  the  caterpillars  you  find  to  see  if  any  of  them 
show  Tachinid  eggs. 

2.  Watch  for  the  development  of  Tachina  Flies  from  the  caterpillars 
you  rear  in  breeding  cages. 

Read :  — 

The  Value  of  Insect  Parasitism  to  the  American  Farmer,  Yearbook  Reprint 
447.    The  Relations  between  Birds  and  Insects,  Yearbook  Reprint  486. 


CHAPTER   XVI 


The  Pollination  and  Fertilization  of  Flowers 

ONE  of  the  most  striking  features  of  the  early  spring 
landscape  in  a  fruit-growing  region  is  that  of  the  great 
white  masses  of  cherry  blossoms.  These  are  to  be  seen  at 
long  distances  wherever  a  cultivated  cherry  tree  is  growing. 
If  you  will  pick  one  of  these  blossoms  and  look  at  it  care- 
fully for  a  moment,  you  will  be 
able  to  see  readily  the  various 
parts  of  which  each  flower  con- 
sists. 

Hold  the  stem  in  one  hand  and 
you  will  see  a  little  green  cup  at 
its  upper  end ;  this  cup  is  called 
the  receptacle.  Around  the  outer 
edges  of  the  cup  are  five  small 
lobes ;  these  are  called  the  sepals. 
They  are  greenish  and  served  to 
protect  the  flower  when  it  was  a 
bud.  In  front  of  the  sepals  and 
between  them  are  the  five  large 

white  petals,  which  make  the  flower  conspicuous.  Inside 
the  petals  are  many  small  pollen-bearing  organs  called 
stamens  ;  each  stamen  consists  of  a  sort  of  stalk  or  filament 
and  a  pollen  bag  or  anther.  Very  likely  the  anther  in 
the  specimen  in  hand  will  have  broken  open  so  that  the 
powdery  pollen  is  plainly  visible.  In  the  center  of  the 
flower  is  a  single  slender  vertical  object  called  the  pistil. 

194 


CHERRY  DLOSSJMS 


THE   FERTILIZATION  OF   FLOWERS 


195 


Pistil 


Sepal 


It  will  be  worth  while  to  cut  away  carefully  the  stamens, 
petals,  sepals,  and  a  portion  of  the  receptacle  on  one  side 
in  order  to  get  a  complete  view  of  the 
pistil.     You  will  then  readily  see,   es- 
pecially through  a  hand  lens,  that  this 
pistil  consists  of  an  enlarged  part  at  the 
bottom  called  the  ovary,  above  which 
is  a  slender  stalk   called  the  style,   on 
the  upper  end  of  which  is  an  enlarged 
portion  called  the  stigma.     If  now  you 
cut  away  carefully  a  piece  of  one  side 
of  the  ovary,  you  will  see  within  a  single  little  egg-shaped 
object  called  the  ovule. 

If  you  look  carefully  with  a  lens  at  the  glistening  surface 
of  the  receptacle,  you  will  probably  see  certain  drops  of 
liquid ;  these  are  drops  of  nectar  which  the  bees  gather 
when  they  visit  the  blossoms  and  carry  home  to  make  into 
honey. 

A  week  or  so  after  the  cherry  trees  have  begun  to  blos- 
som, the  landscape  is  lighted  up  by  the  beautiful  flowers 
of  the  apple  trees.  These  may  be  seen  at  great  dis- 
tances, and  by  their  color  and  odor  serve  to  attract  the 
notice  of  thousands  of  insects,  which  may  be  seen  and 
heard  flying  among  the  blossoms, 
busily  gathering  both  nectar  and 
pollen. 

If  you  examine  an  apple  blossom 
carefully,  you  will  see  that  in  many 
respects  it  resembles  the  flower  of 
the  cherry,  but  differs  in  having  five 
styles  and  stigmas  which  at  their  base  are  united  to  form 
a  compound  ovary.  In  this  ovary  are  five  little  cells  in 
which  the  ovules  are  held.  There  is  thus  one  of  these 


Pollination 


Fertilization 


i96 


FARM   FRIENDS   AND   FARM   FOES 


cells  for  each  style  and  stigma.  You  should  see  the  in- 
teresting nectar  cup  on  the  top  of  the  ovary,  on  which 
glistening  drops  of  nectar  may  generally  be  found. 

SQUASH  BLOSSOMS 

People  are  sometimes  puzzled  over  the  fact  that  cucum- 
bers and  squashes  seem  to  have  so  many  blossoms  in  pro- 
portion to  the  number  of  fruits  produced. 
If  you   examine,    however,    the  flowers 
upon  one  of  these  plants,  you  will  soon 
be  able  to-  tell  the  reason  for  this.     You 
will  find  that  most  of  the  flowers  consist 
CUCUMBER:  POLLEN-     only  of  sepals,  petals,  and  stamens,  and 
BEARING  FLOWER       t^^  guc^  flowers    are  easily  recognized 

from  a  side  view,  by  the  fact  that  there 
is  below  the  blossom  no  little  cucumber 
or  squash  to  develop  later  into  a  fruit. 
These  flowers  are  stamen-bearing  orstam- 
inate  blossoms,  and  in  general  they  are 
smaller  than  the  other  kind  of  flowers 
found  upon  the  same  plants,  which  con- 
sist of  sepals,  petals,  and  a  single  pistil. 
The  ovary  of  the  pistil  which  you  will 
recognize  at  once  as  a  miniature  cu- 
cumber or  squash  is  below  the  main  blossom,  but  has  a 
style  that  runs  up  through  the  center  of  the  flower  and 
bears  upon  its  tip  a  well-developed  stigma.  These  are  the 
seed-bearing  or  pistillate  flowers. 

If  you  should  cut  open  the  ovary  of  one  of  these  pistillate 
flowers,  you  would  find  inside  a  large  number  of  tiny  seed- 
like  bodies  called  the  ovules.  In  order  that  these  ovules 
may  develop  into  seeds,  it  is  necessary  that  some  pollen 
from  the  staminate  blossoms  should  be  placed  upon  the 


CUCUMBER  :  SEED- 
BEARING  FLOWER 


THE  FERTILIZATION  OF  FLOWERS  197 

stigmas  of  the  pistillate  blossoms  and  should  send  down 
through  the  style  certain  pollen  tubes  which  come  in  contact 
with  these  tiny  ovules  and  fertilize  them.  When  they  are 
thus  fertilized,  the  ovules  will  begin  to  develop  into  seeds. 
The  fact  that  these  ovules  are  developing  into  seeds  will 
cause  the  surrounding  ovary,  which  is  the  outer  part  of  the 
little  cucumber  or  squash,  also  to  develop,  and  the  whole 
will  finally  mature  into  a  squash  or  cucumber  with  the  seeds 
inside. 

If  you  look  at  these  flowers  again,  you  will  see  that  the 
pollen  is  sticky  and  well  protected  within  the  lobes  of  the 
yellow  corolla.  You  will  also  see  that  the  stigma  is  likewise 
somewhat  sheltered  by  the  lobes  of  its  corolla,  and  it  will 
easily  be  evident  that  there  is  no  likelihood  that  the  pollen 
will  either  fall  or  be  blown  by  the  wind  from  one  flower  to 
the  other.  How,  then,  is  it  carried  ?  This  is  a  question  you 
can  easily  answer  by  a  few  moments'  observation  on  a 
bright  summer  day.  You  will  see  great  numbers  of  bees 
of  many  sizes  and  kinds  visiting  all  these  flowers.  If  you 
watch  these  bees,  you  will  see  that  their  bodies  are  more 
or  less  dusted  with  pollen  and  that  when  they  enter  the 
pistillate  blossoms,  some  of  this  pollen  is  rubbed  off  upon 
the  stigmas.  Consequently  you  will  know,  that  while  the 
bees  are  gathering  pollen  and  nectar  to  store  up  in  their 
hives  or  nests,  they  are  also  helping  the  plants  by  carrying 
the  pollen  from  one  flower  to  another.  This  carrying  of 
the  pollen  from  stamen  to  stigma  is  called  pollination,  and 
the  bees  which  thus  bring  about  this  pollination  are  called 
pollenizers  or  pollinators. 

If  you  examine  many  strawberry  blossoms,  looking  es- 
pecially to  see  whether  they  all  have  about  the  same  num- 
ber of  pistils  and  stamens,  you  will  probably  find  that 
upon  some  plants  the  flowers  possess  both  sets  of  these 


198 


FARM   FRIENDS   AND   FARM   FOES 


organs,  while  upon  other  plants  you  will  find  that  the 
blossoms  have  an  abundance  of  pistils,  but  very  few  sta- 
mens. If  you  think  of  this  condition  for  a  moment,  you 
will  easily  see  that  in  the  case  of  the  latter,  pollen  must  be 
brought  from  those  flowers  having  many  stamens,  if  the 

little  ovules  are 
to  be  fertilized  and 
the  seeds  to  de- 

vel°P' 

Watch    a 


INSECT  POLLENIZED 


h,a,e 


STRAWBERRY 


PisNllate 

> 


some  bright  day  in  May,  you  will  have  no  trouble  seeing 
how  this  pollen  is  transferred  from  one  blossom  to  the 
other,  for  you  are  very  likely  to  find  a  great  many  insects 
attracted  by  the  white  petals  of  the  strawberry  blossoms, 
gathering,  perhaps  nec- 
tar, perhaps  pollen,  per- 
haps both.  Most  of  these 

insects  will  be  small  bees, 

7AM. 

MAY12 


A    DAY'S 

CHANGES 


10AM 
MAY  12 


possibly  the  common 
honeybees,  in  case  there 
are  hives  of  these  near 
at  hand.  Should  you  IN  A 

follow  a  single  bee  as  she 
goes    from    flower   to 
flower,  you  would  prob- 
ably find  that  she  often      3  p^ 
passes    from    a    pollen-     MAY  12 
bearing    blossom    to    a 
pistil-bearing      blossom, 
and    after   she   has   thus    visited   such    a   flower,    if    you 
would    look   through   a   lens  at  the   stigmas,   you  would 


PEAR 

BLOSSOM 


7A.M. 
MAY  13 


THE   FERTILIZATION  OF   FLOWERS  199 

doubtless  see  that  a  good  deal  of  the  pollen  had  been  left 
upon  these. 

You  certainly  should  be  now  in  a  position  to  understand 
what  is  constantly  happening  in  all  strawberry  beds.  The 
bees  are  busily  at  work  carrying  pollen  from  blossom  to 
blossom,  and  thus  causing  the  fertilization  of  the  little 
ovules  and  their  development  into  seed.  This  growth  of 
the  seed  upon  the  surface  of  the  future  berry  causes  the 
parts  beneath  the  seeds  also  to  develop  into  the  luscious 
fruit. 

You  can  easily  prove  that  this  development  of  the  berry 
will  not  take  place  unless  the  seeds  are  fertilized  by  the 
pollen.  For  if  you  cut  off  the  upper  part  of  the  pistils 
upon  one  side  of  the  berry  as  the  petals  are  unfolding,  so 
as  to  remove  the  stigmas,  and  then  watch  what  happens, 
you  will  be  likely  to  find  that  one  side  of  the  berry  which 
is  left  to  be  fertilized  by  the  bees  will  develop  and  that  the 
other  side  will  not  develop.  You  will  thus  have  been  the 
cause  of  forming  an  abnormal  berry  of  very  little  value, 
but  I  hope  you  will  have  proved  to  yourself  that  the  bees, 
which  are  thus  making  possible  our  crops  of  strawberries, 
are  farm  friends,  without  which  we  should  fare  badly. 

CROSS-FERTILIZED  FLOWERS 

It  is  evident  that  in  the  case  of  the  squashes  and  cucum- 
bers, as  well  as  of  the  strawberries,  the  pollen  that  occurs 
upon  the  stigmas  of  a  seed-bearing  flower  must  come 
from  another  flower.  When  pollen  is  thus  carried  from 
one  flower  to  another,  the  blossom  is  said  to  be  cross- 
pollenized  and  the  ovules  as  a  result  are  cross-fertilised ; 
that  is,  the  ovules  are  fertilized  by  pollen  from  another 
blossom  which  is  usually  upon  another  plant.  When  a 
flower  is  pollenized  and  fertilized  by  the  pollen  from  its 


200  FARM  FRIENDS  AND   FARM  FOES 

own  anthers,  it  is  said  to  be  self-pollenized  and  the  ovules 
are  said  to  be  self-fertilized. 

As  a  matter  of  fact,  the  great  majority  of  flowering 
plants  are  cross-fertilized.  Many  of  them  have  special 
devices  for  preventing  self-pollination.  These  devices 
include  the  separation  of  the  stamens  and  pistils  in  differ- 
ent flowers,  as  in  the  case  of  the  squashes  and  cucumbers, 
the  maturing  of  the  stamens  and  pistils  at  different  times, 
or  a  difference  in  length  of  stamens  and  pistils  which  pre- 
vents the  pollen  from  getting  upon  the  stigmas.  One  of 
the  commonest  methods  that  nature  employs  in  preventing 
self-fertilization  is  in  rendering  the  pollen  incapable  of 
fertilizing  the  ovules  of  the  flower  in  which  it  developed. 
Such  flowers  are  said  to  be  self-sterile,  and  very  commonly 
none  of  the  pollen  upon  a  plant  is  able  to  fertilize  the 
ovules  of  any  of  the  flowers  upon  that  plant.  Not  only 
this,  but  in  many  cases  the  pollen  of  a  certain  variety  of 
apple,  pear,  or  plum  is  incapable  of  fertilizing  any  other 
flowers  of  the  same  variety,  even  upon  different  trees. 
In  such  cases  the  whole  variety  is  said  to  be  self-sterile 
and  must  be  pollenized  by  flowers  of  some  other  variety. 

The  discovery  that  a  large  proportion  of  the  varieties  of 
tree  fruits  are  self -sterile  is  one  of  the  most  important  re- 
cent developments  in  our  knowledge  of  fruit  growing.  It 
has  been  observed  for  a  longtime  that  the  variety  of  plums 
called  the  Wild  Goose,  when  planted  alone,  will  not  set  fruit, 
even  though  there  be  many  trees  near  together.  It  had 
also  been  noticed  that  when  other  varieties  of  plums  were 
planted  near  the  Wild  Goose  trees,  the  latter  commonly 
produced  abundant  crops.  An  investigation  of  the  cause 
of  this,  undertaken  by  M.  B.  Waite,  of  the  United  States 
Department  of  Agriculture,  showed  that  this  lack  on  the 
part  of  the  Wild  Goose  trees  was  due  chiefly  to  the  fact 


THE  FERTILIZATION  OF   FLOWERS  201 

that  the  variety  is  self-sterile,  and  requires  for  the  develop- 
ment of  fruit  the  transfer  of  pollen  from  some  other  sort  of 
plum. 

Other  investigators  have  also  made  further  studies  of  the 
subject,  the  more  important  of  these  having  been  made  by 
Bailey,  Fletcher,  Kerr,  and  Waugh,  with  results  which  are 
of  great  importance  to  every  fruit  grower. 

It  has  been  pretty  conclusively  shown  that  in  the  case  of 
a  large  proportion  of  orchard  fruits,  a  much  more  abundant 
crop  is  produced  where  cross-pollination  with  another  va- 
riety takes  place.  It  has  also  been  shown  that  in  many 
cases  there  is  a  decided  increase  in  the  size  of  such  fruits. 
This  increase  is  so  marked  that  it  is  well  worth  while 
for  any  fruit  grower  to  take  it  into  consideration  in  plan- 
ning his  orchard.  The  increase  in  size  is  believed  by 
Fletcher  to  be  due  to  the  fact  that  "  the  foreign  pollen  gen- 
erally stimulates  the  fruit  to  a  better  growth,  because  it  is 
more  acceptable  to  the  pistils,  not  because  it  carries  over 
the  size-character  of  the  variety  from  which  it  came." 

In  selecting  varieties  of  fruit  trees  with  reference  to 
cross-fertilization  it  is  important  to  choose  those  which 
blossom  at  the  same  time. 


AGENCIES  THAT  CARRY  POLLEN 

There  are  three  principal  agencies  concerned  in  bring- 
ing about  the  cross-pollination  of  plants.  These  are  :  — 

i.  The  wind  which  carries  the  pollen  for  a  large  propor- 
tion of  the  forest  trees  that  blossom  early  in  spring,  but 
which  apparently  has  comparatively  little  to  do  with  the 
cross-pollination  of  the  flowers  of  most  fruit  trees  and  cul- 
tivated plants.  Such  plants  are  said  to  be  ancmophilcns  or 
wind-loving  plants. 


202  FARM   FRIENDS   AND   FARM   FOES 

2.  Certain  birds,  especially  humming  birds,  which  carry 
pollen  from  flower  to  flower  for  a  comparatively  few  species 
in  temperate  regions,  although  apparently  in  tropical  re- 
gions there  are  many  species  so  pollenized.     Such  plants 
are  said  to  be  ornimopliilous  or  bird-loving  plants. 

3.  Insects  of  many  kinds,  especially  bees,  wasps,  butter- 
flies, and  flies,  which  carry  the  pollen  for  the  great  majority 
of  flowering  plants  and  in  so  doing  confer  an  inestimable 
benefit  upon  mankind.      Such  plants  are  said  to  be  ento- 
mophilons  or  insect-loving  plants. 


LEG  OF  BEE 


CHAPTER   XVII 
The  Insect  Pollinators 

BY  far  the  most  important  insect  pollinators  of  cultivated 
crops  are  the  bees  of  the  order  Hymenoptera.  The  bees 
form  a  superfamily  called  Apina,  the  members  of  which  as  a 
rule  are  known  by  the  fact  that  under  a  lens  the  hairs  which 
cover  their  bodies  are  seen  to  be  provided  with  many  minute 
barbs.  In  most  cases,  also,  the  first  joint  of  the  hind  tarsi 
is  expanded  and  hairy,  being  adapted  to  carrying  pollen. 
The  tarsi  are  the  short  joints  at  the  ends  of  the  legs,  and 
the  first  is  next  to  the  second  large  joint  of  the  legs,  which 
in  a  great  many  bees  is  especially  developed  into  a  so-called 
pollen  basket.  This  may  readily  be  seen  by  examining  the 
hind  legs  of  a  bumblebee  or  other  large  bee.  The  barbed 
hairs  over  the  body  are  obviously  an  adaptation  for  carry- 
ing pollen,  and  they  enable  these  insects  to  become  the 
most  efficient  of  all  pollen  carriers. 

The  bees,  as  a  whole,  are  divided  into  two  great  groups 
or  families  —  the  short-tongued  bees  ( Andrenidae)  and  the 
long-tongued  bees  (Apidae). 

The  short-tongued  bees  collect  nectar  and  pollen  from  a 
great  variety  of  flowers,  but  they  are  not  able  to  insert  their 
tongues  into  the  long  tubes  of  flowers  in  which  the  nectar 
is  deeply  concealed.  These  bees,  for  the  most  part,  build 
their  nests  in  the  ground,  burrowing  holes  into  which  they 
carry  a  mixture  of  nectar  and  pollen  upon  which  the  larval 
bees  develop.  Most  of  these  short-tongued  bees  are  very 
small,  and  many  of  them  may  readily  be  found  by  a  few 

203 


204  FARM   FRIENDS  AND   FARM  FOES 

minutes'  inspection  of  flowers  in  which  the  nectar  is  easily 
accessible. 

The  long-tongued  bees  may  for  our  present  purpose  be 
arranged  into  two  principal  groups,  those  that  live  solitary 
lives  and  those  that  live  social  lives.  The  former  are 
comparatively  few  and  so  are  of  little  importance  as 
pollinators  of  cultivated  crops.  One  of  the  most  distinc- 
tive forms  is  that  of  the  Leaf  Cutter  Bees,  which  have  the 
curious  habit  of  cutting  out  pieces  of  leaves,  to  use  in 
building  their  nests.  Roses  and  other  plants  often  show 
leaflets  in  which  a  rounded  piece  has  been  neatly  cut  out. 
This  is  generally  the  work  of  one  of  these  Leaf  Cutter 
Bees.  These  insects  may  be  recognized  from  the  fact 
that  the  under  side  of  the  body  is  covered  with  a  brush  of 
hairs,  which  is  used  in  collecting  the  pollen  for  provision- 
ing the  nests. 

SOCIAL  BEES 

But  the  insects  to  which  mankind  is  indebted  beyond  all 
others  for  carrying  pollen  are  the  social  bees,  of  which  the 
familiar  Bumblebee  and  the  domestic  Honeybee  are  typical 
examples.  These  bees  live  in  colonies,  a  single  colony 
often  consisting  of  a  vast  number  of  individuals.  To  a 
large  extent  these  insects  have  at  least  three  distinct  forms 
in  each  colony.  In  addition  to  the  true  males  and  females 
or  the  drones  and  queens,  there  are  great  numbers  of 
workers,  which  are  generally  smaller  in  size  and  which 
do  most  of  the  work  of  gathering  nectar  and  pollen  to 
provision  the  nests  with  honey  and  bee  bread. 

The  yearly  cycle  in  the  life  of  the  Bumblebees  furnishes 
a  good  illustration  of  the  habits  of  the  social  bees.  Early 
in  spring  you  may  often  find  the  large  queen  Bumblebees 
flying  slowly  about  close  to  the  surface  of  the  ground  in  a 


THE  INSECT  POLLINATORS  205 

more  or  less  zigzag  fashion.  They  often  alight  and  explore 
some  nook  or  cranny  that  seems  to  promise  a  favorable 
situation  for  a  nest.  These  queen  Bumblebees  are  the 
only  kind  that  have  been  able  to  live  through  the  winter, 
and  they  have  been  sheltered  in  some  deserted  mouse  nest 
or  similar  covering. 

When  the  queen  Bumblebee  finds  a  place  that  she  thinks 
suitable  for  a  new  nest,  she  adopts  it  for  the  home  of  her 
future  colony.  Then  she  flies  to  the  early  spring  flowers 
and  gathers  nectar  and  pollen  which 
she  brings  to  her  nest  and  of  which 
she  forms  little  balls  of  "  bee  bread." 
This  consists  simply  of  a  sort  of  paste 
made  by  mixing  honey  and  pollen 
together.  Upon  each  of  these  food 
balls,  the  queen  bee  deposits  an  egg. 

Very    shortly  each    of   these  eggs 

hatches  into  a  tiny  footless  larva  that  BUMBLEBEE     SHOWING 
•?  POLLEN  MASSES  ON 

feeds  upon  the  bee  bread  and  gradu-      HIND  LEGS 

ally  increases   in   size.     Before  very 

long  it  becomes  full-grown  as  a  larva  and  changes  to  a 
pupa  or  chrysalis,  and  a  little  later  into  an  adult  Bum- 
blebee. These  adults  are  smaller  than  the  queens  and  are 
the  first  of  the  season's  broods  of  worker  Bumblebees. 

These  worker  bees  soon  undertake  a  large  part  of  the 
care  of  the  colony.  They  form  the  curious  and  character- 
istic cells  which  are  found  so  abundantly  in  Bumblebees' 
nests  late  in  summer,  and  they  gather  nectar  and  pollen 
for  the  food  of  the  young.  The  queen  bee  is  thus  left 
free  to  deposit  eggs  for  more  broods  of  future  workers. 

Thus  the  colony  passes  through  the  summer,  constantly 
increasing  in  numbers  and  all  working  together  for  the 
good  of  the  great  bee  family.  They  visit  flowers  of  many 


206  FARM   FRIENDS   AND   FARM   FOES 

different  sorts,  especially  those  in  which  the  nectar  is 
deeply  secreted,  as  they  are  able  to  reach  such  nectar  by 
means  of  their  very  long  tongues.  They  go  about  from 
day  to  day,  performing  for  mankind  a  service  of  inesti- 
mable value  and  deserving  his  support  and  protection. 

Toward  the  end  of  summer  a  brood  of  males  and  females, 
or  drones  and  queens,  is  developed.  These  come  forth 
late  in  summer  or  early  in  autumn,  visiting  flowers  freely 
along  with  the  workers.  All,  however,  except  the  queens, 
perish  when  cold  weather  comes,  and  only  such  queens  as 
find  adequate  shelter  are  able  to  live  through  the  winter  to 
begin  again  the  cycle  of  the  colony. 

HONEYBEES  AND  RELATED  INSECTS 

There  are  many  kinds  of  wild  bees,  besides  the  bumble- 
bees, which  are  useful  in  the  pollination  of  crops.  In 
many  thickly  settled  communities,  however,  these  are  not 
so  important  as  are  the  familiar  hive  bees,  which,  from 
the  point  of  view  of  usefulness  to  man,  have  the  great  ad- 
vantage that  they  can  be  introduced  into  cleanly  cultivated 
regions  where  there  are  comparatively  few  places  for  wild 
bees  to  breed.  In  many  greenhouses,  hives  of  bees  are 
regularly  kept  to  bring  about  the  pollination  of  cucumber 
crops,  a  process  that  formerly  required  much  hand  work  on 
the  part  of  men.  Outdoors  in  large  orchards,  such  hives 
seem  almost  as  essential  for  insuring  the  cross-pollination 
of  the  millions  of  flowers  to  be  found  upon  the  hundreds  or 
thousands  of  apple  trees.  These  bees,  of  course,  have  the 
additional  advantage  that  they  furnish  honey  to  the  owner. 

There  are  many  other  members  of  the  order  Hymenop- 
tera,  which  may  commonly  be  found  upon  the  flowers  of 
plants,  seeking  nectar  or  pollen,  or  both.  The  wasps, 
hornets,  yellow  jackets,  sawflies,  and  ichneumon  flies  may 


THE  INSECT  POLLINATORS  207 

all  be  found  at  times  upon  flowers,  either  wild  or  cultivated. 
So  far  as  cultivated  crops  are  concerned,  however,  these 
insects  are  much  less  important  than  are  the  bees,  both  on 
account  of  their  smaller  numbers  and  the  lack  of  barbed 
hairs  upon  their  bodies  for  catching  and  carrying  the 
pollen. 

TWO-WINGED  FLIES 

In  the  great  order  of  two- winged  flies  (Diptera)  there 
are  hundreds  of  species  that  freely  visit  flowers.  Some 
come  for  nectar,  some  for  pollen,  some  for  both.  The  legs 
and  bodies  of  many  of  these  flies  are  furnished  with  hairs, 
to  which  the  pollen  becomes  attached  and  by  means  of 
which  it  is  carried  from  the  anthers  of  one  blossom  to  the 
stigmas  of  another.  These  flies,  as  a  rule,  however,  visit 
those  flowers  in  which  the  nectar  is  more  or  less  exposed 
in  shallow  cups,  and,  except  perhaps  in  the  case  of  certain 
fruit  crops,  they  are  not  nearly  so  important  as  pollinators 
as  are  the  social  bees. 

BUTTERFLIES  AND  MOTHS 

In  the  great  order  of  scale-winged  insects,  the  moths  and 
butterflies  (Lepidoptera),  the  great  majority  of  species  are 
especially  adapted  to  living  as  adults  upon  the  nectar  of 
flowers.  Consequently,  there  are  many  plants  the  blossoms 
of  which  are  especially  adapted  to  cross-pollination  by 
means  of  butterflies  or  moths.  These  insects  have  long 
sucking  tubes,  each  of  which  is  commonly  coiled  like  a 
watch  spring  on  the  under  side  of  the  insect's  head.  When 
the  butterfly  or  moth  visits  a  flower,  however,  it  uncoils  the 
tongue  and  projects  it  forward  to  reach  the  nectar  of 
the  blossom.  Often  these  tongues  are  of  extraordinary 
length,  and  so  it  is  not  surprising  to  find  that  the  flowers 


208  FARM  FRIENDS  AND   FARM  FOES 

especially  adapted  to  the  visits  of  moths  and  butterflies 
commonly  have  their  nectar  deeply  concealed  where  it 
cannot  be  reached  by  most  other  insects. 

The  great  group  of  hawk  moths  or  sphinx  moths  is  one 
of  the  most  interesting  from  the  point  of  view  of  pollina- 
tion. By  examining  a  beautiful  Easter  lily,  one  can  readily 
see  the  relation  between  these  moths  and  the  pollination  of 
such  flowers. 

"  If  you  remove  one  side  of  the  white  flower  cup,  you 
will  see  that  the  pistil  consists  of  a  long  style  running  the 
whole  length  of  the  flower,  with  the  sticky  stigmas  at  the 
end.  Grouped  on  the  sides  are  the  stamens,  which  also 
have  long  filaments  tipped  with  the  anthers  at  the  mouth 
of  the  flower.  Evidently  no  other  insects  can  get  the 
nectar  at  the  base  of  the  cup ;  the  sphinx  moths  are  the 
only  ones  adapted  to  derive  benefit  from  such  a  blossom. 
But  for  them  the  adaptation  is  perfect.  The  tongues  of 
the  larger  species  will  reach  the  honey,  while  their  heads 
come  in  contact  with  the  anthers  or  stigmas  and  perform 
the  pollenizing  office. 

"  These  moths  are  not  day-fliers :  they  appear  at  dusk, 
and  during  the  early  evening  they  shoot  like  meteors  from 
blossom  to  blossom,  hovering  hawklike  in  the  mouth  of 
the  flower,  while  the  long  tongue  is  inserted  to  extract  the 
hidden  nectar.  The  immaculate  whiteness  of  the  lilies 
renders  them  conspicuous  in  the  twilight :  they  then  shed 
their  perfume  most  abundantly,  and,  in  some  species  at 
least,  produce  the  most  nectar.  These  methods  the  lily 
has  developed  to  attract  her  pollen-carrying  guests.  The 
latter  also  are  assisted  in  the  adaptation  ;  their  long  tongues, 
the  shape  of  their  heads,  their  large  eyes,  all  are  useful  to 
the  lily,  while  the  swiftness  of  their  flight  and  the  business- 
like way  in  which  they  utilize  the  few  hours  during  which 


THE  INSECT  POLLINATORS 


209 


they  are  abroad  enable  them  to  pollenize  a  large  number 
of  blossoms  in  a  short  time."  1 

Some  of  the  other  lilies  show  similar  adaptations  to  the 
visits  of  sphinx  moths,  and  many  of  the  honeysuckles  and 
other  flowering  plants  are  adapted  to  pollination  by  such 
visitors. 

1  Weed,  Ten  New  England  Blossoms. 


EASTER  LILY 


210  FARM  FRIENDS  AND   FARM  FOES 

OBSERVATIONS  FOR  PUPILS 
THE  APPLE 


1.  Make  a  careful  study  of  some  apple  blossoms.     See  if  you  can 
identify  all  of  these  parts  :  — 

The  calyx  lobes,  which  represent  the  sepals. 

The  petals. 

The  stamens,  each  with  filament  and  anther,  the  latter  containing 

pollen. 
The  pistils,  united  in  the  ovary,  with  the  lower  part  of  the  styles 

also  united  and  bearing  a  fringe  of  hairs,  then  separating  and 

each  having  the  stigma  at  the  top. 
The  nectar  cup  on  the  top  of  the  ovary. 

2.  See  if  you  can  determine  how  the  nectar  is  protected  from  ants 
and  wingless  insects  by  the  palisade  of  filaments  around  the  outside  and 
the  hairs  upon  the  united  styles  in  the  middle. 

Thrust  a  sharp  pencil  point  down  through  the  hairs  to  see  how  the 
long-tongued  bee  could  get  at  the  nectar  while  the  short-tongued  ant  is 
excluded  from  it. 

3.  Watch  the  apple  trees  on  a  bright  day  to  see  what  sorts  of  insects 
you  find  visiting  the  blossoms. 

Make  a  list  of  as  many  different  kinds  as  you  recognize.  Are 
any  of  the  bees  collecting  honey  ?  Can  you  see  them  thrust  their 
tongues  down  to  get  the  nectar  ? 

4.  When  it  rains  much  of  the  time  during  the  blossoming  of  the 
apple  trees,  are  the  bees  able  to  carry  the  pollen  as  well  as  when  the 
weather  is  fair  ? 

B 

i.  Tell  or  write  a  little  story  with  this  title  :  The  Mission  of  the 
Apple  Petals.  Follow  some  such  outline  as  this  :  — 

The  pistil  in  the  bud. 

The  nectar  cup  that  it  covers. 

The  purpose  in  attracting  the  bees. 

The  carrying  of  the  pollen  by  the  bees. 

The  fertilization  of  the  flowers. 

The  falling  away  of  the  petals. 

The  development  of  the  fruit. 


THE  INSECT  POLLINATORS  211 

2.  If  your  story  is  written,  illustrate  it  by  such  drawings  of  petals  and 
flowers  as  seem  to  you  desirable. 

3.  Read :  — 

The  Pollination  of  Pomaceous  Fruits,  Yearbook  Reprint  157. 

THE  CHERRY  AND  THE  PLUM 

Make  a  study  of  the  structure  of  the  blossom  and  its  relation  to 
insect  visitors  in  the  case  of  the  cherry  or  the  plum.  Follow  in  a 
general  way  the  outline  given  above  for  the  apple. 

THE  STRAWBERRY 


1 .  Examine  a  number  of  strawberry  blossoms  and  see  if  you  can  find 
some  in  which  there  are  many  pistils  and  but  few  stamens,  and  others 
in  which  there  are  both  pistils  and  stamens  in  abundance. 

2.  Watch  the  flowers  on  a  bright  day  to  see  what  insects  are  visiting 
them.     Can  you  tell  whether  the  insects  are  gathering  nectar  or  pollen 
or  both.     Do  you  see  any  pollen  on  the  bodies  or  legs  of  the  bees  ? 

3.  Watch  a  bee  carefully  as  it  goes  from  one  flower  to  another.    Would 
it  be  likely  that  some  pollen  would  be  brushed  upon  the  stigmas  as  the 
bee  gathers  nectar  ? 

4.  How  does  the  length  of  the  blossoming  period  of  the  strawberry 
compare  with  that  of  the  apple  ?     Are  there  more  days  for  the  bees  to 
cross-pollenize  the  strawberry  than  the  apple  ? 

5.  Tie  a  bit  of  mosquito  netting  or  cheesecloth  over  one  of  the 
pistillate  strawberry  blossoms  before  it  opens  so  as  to  exclude  any  insect 
visitor.     See  if  a  well-developed  strawberry  is  formed  after  the  petals 
fall  off. 

B 

1.  Tell  or  write  a  little  story  with  some  such   title   as   this  :  The 
Strawberry  and   the  Bees.     Show  how  much  we  owe  to  the  bees  for 
carrying  the  pollen  from  flower  to  flower. 

2.  Illustrate  your  story  with  drawings  of  bees  and  strawberry  blos- 
soms. 

CUCUMBERS  AND  SQUASHES 
A 

i.    Examine  carefully  all  the  flowers  upon  a  single  long  stem  of  a 
cucumber,    squash,    pumpkin,   or   melon   plant.      How    many    of    the 


212  FARM  FRIENDS  AND   FARM  FOES 

blossoms  are  pollen-bearing  or  staminate,   and  how  many  are   seed- 
bearing  ?     You  may  know  the  latter  by  the  little  fruit  below  the  flower. 

2.  On  a   bright   day   see   what   kinds   of  insects   are   visiting  the 
flowers.     Are  they  mostly  bees  ?    Do  you  find  any  bumblebees  ?    Watch 
one  of  the  bees  as  it  comes  out  of  a  pollen-bearing  blossom  and  see  if 
you  can  see  any  pollen  upon  its  body. 

3.  Watch  one   of  the  bees  as  it  leaves   a  pollen-bearing  blossom. 
f  Do  you  find  that  it  ever  goes  to  a  seed-bearing  blossom  ?     See  if  any 

of  the  pollen  is  rubbed  from  the  body  of  the  bee  upon  the  stigma  of 
the  flower. 

4.  See  if  any  bees  are  at  work  on  damp  days  when  there  is  a  little 
mist  or  rain  in  the  air.     If  any  bees  are  at  work,  what  kinds  are  they? 

B 

1.  Write  or  tell  a  little  story  with  this  title:  The  Pollination  of  the 
Squash  Blossom.     If  it  is  a  cucumber  you  observed,  make  it :  The  Pol- 
lination of  the  Cucumber  Blossom. 

Follow  this  outline  :  — 

The  pollen-bearing  flower. 

The  seed-bearing  flower. 

The  need  of  the  transfer  of  pollen. 

The  nectar  that  attracts  the  bees. 

The  color  that  advertises  the  nectar. 

The  bees  that  carry  the  pollen. 

The  wilting  of  the  pollen-bearing  blossoms. 

The  growth  of  the  fruit. 

2.  Make  a  drawing  of  the  side  view  of  each  kind  of  flower,  and,  if  you 
have  time,  a  longitudinal  sectional  view  of  the  seed-bearing  ovary. 


PART    III 

FRIENDS   AND    FOES    AMONG   THE 
FUNGI 


THE  BOOKLET  ON  FUNGI 

In  addition  to  the  drawings  and  written  pages  suggested  under  Observa- 
tions for  Pupils  it  is  easy  to  enrich  the  booklet  on  fungi  by  mounted  speci- 
mens of  leaves  and  other  parts  of  plants  affected  by  various  fungous 
parasites.  These  occur  everywhere  in  autumn,  so  they  are  very  readily 
obtained.  They  may  be  pressed  for  a  few  days  between  papers,  changing 
daily,  and  then  mounted  by  strips  of  gummed  labels.  The  name,  locality, 
date,  and  collector  should  be  printed  on  each  sheet. 


CHAPTER   XVIII 


Mushrooms,  Toadstools,  and  Molds 

EVERY  one  is  familiar  with  the  peculiar  umbrella-like 
plants  called  tpadstools  and  mushrooms,  which  may  be  found 
abundantly  during  damp  weather,  especially  in  early  autumn, 
in  fields  and  woods.  They  differ  from  our  common  plants 
in  that  they  have  none  of  the 
green  coloring  matter  called 
chlorophyl  by  means  of  which 
the  higher  plants  carry  on 
the  processes  of  their  life. 

These  toadstools  and  mush- 
rooms belong  to  the  great 
group  of  fungi  —  a  group 
which  includes  a  large  num- 
ber of  species  of  plants.  The 
fungi  rank  lower  in  the  scale 
of  life  than  the  trees  and 
herbs  which  we  commonly 

have  in  mind  when  we  speak  of  plants,   but  they 
many  important  purposes  in  the  economy  of  nature. 

If  you  will  place  a  well-developed  toadstool  of  the  general 
type  of  the  specimen  shown  in  the  picture  above  in  the 
position  in  which  it  grew,  upon  a  piece  of  white  paper,  and 
leave  it  for  a  day  or  two,  the  paper  will  probably  be  covered 
with  a  fine  dark  powder.  A  similar  powder  will  be  found 
upon  the  thin  plates  hanging  down  from  the  upper  part 
of  the  toadstool.  If  some  of  this  powder  be  placed  under 

215 


serve 


2l6 


FARM   FRIENDS   AND   FARM   FOES 


a  high  power  of  the  microscope,  it  will  be  seen  to  consist 
of  great  numbers  of  very  small,  roundish  particles.  These 
are  the  spores  or  reproductive  bodies  of  the  mushroom,  and 
they  may  be  likened  in  their  relation  to  the  life  of  the 
fungus  to  the  seeds  of  the  higher  plants. 

When  these  spores  are  produced  by  the  toadstool  out- 
doors, millions  of  them  are  blown  away  by  the  wind,  or 
washed  away  by  the  rain.  When  one  of  them  chances  to 

fall  upon  rich  earth,  it 
sends  out  a  little  tube,  in 
much  the  same  way  that 
a  sprouting  seed  sends 
out  its  germinating  radi- 
cle. After  this  tube  has 
grown  between  the  soil 
particles  a  little  way,  it 
develops  branches  that 
push  about  between  the 
decaying  bits  of  organic 
matter  and  absorb  mate- 
Soil  washed  from  "spawn"  and  "buttons,"  rials  of  growth  from  them, 
showing  the  minute  young  "buttons"  at-  -r-,  r  ,,  .  ,,  , 

tached  to  the  strands  of  mycelium  Because  Ot  this  the  toad- 

stool  is  called  a  sapropJiyte 

—  a  plant  living  upon  decaying  organic  matter.  These 
branches  in  turn  send  out  other  branches  and  thus  form 
the  spawn,  or  vegetative  portion  of  the  fungus.  This  is 
also  often  called  the  mycelium. 

This  spawn  continues  to  develop  beneath  the  surface  of 
the  soil  for  a  while,  until  at  certain  places  there  are  special 
growths  from  each  of  which  one  or  more  toadstools  are 
produced,  often  appearing  suddenly  above  the  surface. 

Each  toadstool  consists  of  a  stem,  above  which  is  a 
wide  top  suggestive  of  an  umbrella.  This  top  bears  on 


MUSHROOM 


MUSHROOMS,   TOADSTOOLS,   AND   MOLDS        217 


the  under  side  curious  thin  vertical  plates,  called  gills  or 
lamella.  On  these  plates  the  spores  develop,  falling  from 
them  to  the  ground  or  being  blown  away  by  the  winds. 
The  plant  has  now  fulfilled  the  purpose  of  its  existence, 
and  it  rapidly  decays  —  a  process  much  hastened  by  the 
numerous  insect  larvae  that  feed  upon  the  inner  tissues  of 
the  fungus. 

On  most  toadstools  and  mushrooms  there  may  be  found 
a  ring  of  thin  tissue  with  ragged  edges,  hanging  from  the 
upper  part  of  the  stem.  This  is  the  remnant  of  a  delicate 
membrane,  called  the  velum,  or  veil,  which  covered  the 
surface  of  the  cap  during  its  rapid  growth. 

Those  species  of  these  fleshy  fungi  which  are  not 
poisonous  and  are  good 
to  eat  are  called  mush- 
rooms, while  the  poison- 
ous ones  are  commonly 
called  toadstools.  No 
general  rule  can  be  given 
for  distinguishing  the 
edible  from  the  poison- 
ous kinds. 

Perhaps  a  clearer  idea 
of  the  relation  between         MYCELIUM  OF  THE  COMMON  MOLD 

the    mycelium    of   a    fun-     From  the  spore  lying  near  the  middle  of  the 

gus  and  its  reproductive 

spores  may  be  obtained 

from  the   picture  above 

of  one  of   the  common 

molds    that   grow   upon 

bread  or  other  materials  in  dark,  moist  situations.     The 

branching  threads  of  the  mycelium  are  spread  out  over  a 

wide  space.     At  certain  points  rise  vertical  columns.     On 


figure,  and  strongly  swollen,  one  sees  the 
thick  threads  of  the  mycelium  arise.  From 
the  level  of  the  mycelium  arise  three  verti- 
cal, fertile  stalks,  a,  b,  c,  of  which  a  is  still 
very  young  and  that  at  b  is  already  produc- 
ing a  case  containing  many  spores.  All 
highly  magnified. 


2i8  FARM  FRIENDS  AND   FARM   FOES 

the  top  of  these  the  spores  are  produced.  Compare  it  with 
an  apple  tree :  the  mycelium  corresponds  in  a  way  to  the 
roots ;  the  vertical  column  to  the  trunk ;  the  spores  to  the 
seeds  in  the  fruit. 

Can  you  not  see  that  this  mold  is  really  a  plant,  though 
it  lacks  the  green  coloring  matter  of  our  more  familiar 
plants  ? 

PARASITIC  FUNGI 

The  toadstools,  mushrooms,  and  molds  are  all  fungi  that 
live  at  the  expense  of  dead  or  decaying  plant  or  animal 
materials.  They  are  not  of  very  great  interest  to  agricul- 
ture. I  have  described  them  here  to  lead  to  a  clearer 
knowledge  of  certain  other  fungi  that  are  of  exceeding  im- 
portance to  growing  crops.  These  are  the  fungi  that  develop 
at  the  expense  of  the  tissues  of  living  plants ;  that  is,  they 
are  parasites  rather  than  saprophytes.  They  bring  disease 
and  death  to  many  crops  and  cause  the  myriad  forms  of 
fungous  diseases  that  destroy  millions  of  dollars  worth  of 
farm  and  garden  produce  every  year. 


A  DYING  MUSHROOM 


v     CHAPTER  XIX 
The  Downy  Mildews 

THE  group  of  fungi  commonly  called  the  Downy  Mil- 
dews includes  several  of  the  most  destructive  fungous 
enemies  of  cultivated  crops.  These  parasites  grow  at  the 
expense  of  the  vital  tissues  of  the  host  plants,  penetrating 
between  the  cells  in  all  directions  and  sending  into  the 
cells  curious  projections  that  absorb  their  contents.  They 
produce  summer  spores  in  untold  billions,  to  be  widely 
scattered  so  quickly  that  whole  fields  may  seem  to  succumb 
in  a  single  day.  The  technical  name  of  the  great  group  to 
which  they  belong  is  Phycomycetes. 

POTATO  BLIGHT 

In  America  the  Downy  Mildew  of  the  Potato  probably 
causes  the  greatest  loss  of  any  of  these  parasites,  espe- 
cially in  the  Eastern  states.  During  recent  years  this 
disease  has  been  generally  called  the  Late  Blight  to  dis- 
tinguish it  from  the  Early  Blight  of  Potatoes  due  to  a 
different  fungus.  This  Late  Blight  causes  not  only  the 
death  of  leaves  and  stems,  but  also  the  decay  of  the  tubers. 
It  destroys  millions  of  dollars  worth  of  potatoes. 

To  get  an  idea  of  what  happens  in  a  potato  field  when  it 
seems  suddenly  to  blight,  let  us  assume  that  we  have  be- 
fore us  a  green  and  healthy  plant  in  August.  Its  leaves 
are  busily  engaged  absorbing  the  sunshine  and  converting 
the  unorganized  substances  from  the  soil,  moisture,  and  air 
into  highly  organized  materials.  These  it  is  sending  down 

219 


22O 


FARM  FRIENDS  AND  FARM  FOES 


through  its  lusty  stalks  to  the  little  tubers  at  the  ends  of 
the  underground  stems,  there  to  be  stored  in  cells  as 
starch.  All  over  the  surfaces  of  the  leaves  are  the  tiny 
openings  or  breathing  pores  through  which  the  air  gets  to 
the  leaf  cells  and  through  which  the  surplus  water  may  es- 
cape as  vapor.  The  plant  is 
healthy  and  vigorous  and  ap- 
parently enjoying  its  existence. 
But  one  day  a  breeze  springs 
up  that  carries  particles  of  dust 
from  field  to  field.  In  the  dust 
are  many  summer  spores  of  the 
mildew  fungus,  some  of  which 
are  caught  on  the  surface  of 
the  potato  leaves.  The  breeze 
is  followed  by  a  summer  shower 
that  soon  passes,  leaving  the 
foliage  wet  with  glistening 
drops  that  reflect  the  hues  of 
the  rainbow  as  the  sun  comes  out  again. 

In  one  of  these  drops  a  Downy  Mildew  spore  is  held. 
It  needed  only  the  moisture  to  cause  it  to  produce  curious 
swarm  spores  that  swim  about  in  the  water  and  finally 
germinate,  each  by  sending  out  a  slender  tube.  The  tube 
lengthens,  the  end  creeping  along  till  it  reaches  one  of  the 
open  breathing  pores.  It  enters  this  and  then  begins  to 
grow  rapidly,  sending  branching  threads  between  the  leaf 
cells  in  all  directions.  These  threads  form  the  mycelium 
of  the  fungus.  They  send  into  the  cells  short  suckerlike 
branches  through  which  the  contents  of  the  cells  are 
absorbed.  Thus  the  threads  of  the  fungus  penetrate 
through  all  the  tissues  of  the  leaf.  Finally  they  run 
through  the  petiole  to  the  main  stalk  and  perhaps  down 


POTATO  LEAF  AFFECTED  WITH 
LATE  BLIGHT 


THE   DOWNY   MILDEWS 


221 


the  stalk  to  the  forming  tuber  below.  Wherever  they  go, 
they  cause  the  death  of  the  cells  of  living  tissue,  breaking 
them  up,  turning  them  brown,  and  causing  a  foul  odor  to 
be  given  off.  In  the  case  of  the  stalks  and  tubers  the 
result  appears  as  a  sort  of  rot. 

The  prosperous,  healthy  plant  is  thus  stricken  with  a 
sudden  sickness  that  may  well  be  called  a  blight.  The 
tubers  are  no  longer  able  to  increase 
in  size  through  the  addition  of  starch 
cells.  A  field  thus  blighted  is  a 
sight  that  may  well  bring  dismay  to 
the  owner  who  had  hoped  for  a 
bountiful  harvest. 

But  the  parasite  is  not  yet  done 
with  its  stricken  host.  All  this 
growth  of  mycelium  has  been  but 
a  preparation  for  the  development 
of  the  reproductive  spores,  just  as 
the  growth  of  the  mushroom  myce- 
lium beneath  the  soil  surface  is  but  a 
preparation  for  the  sending  up  of 
the  spore-bearing  mushroom.  The  mycelium  in  the  leaves 
sends  out  to  the  surface  vertical  branches  that  bear  upon 
their  tips  the  tiny  summer  spores.  These  mature  quickly 
and  are  readily  carried  away  by  the  slightest  breeze.  Thus 
the  disease  is  able  to  spread  rapidly  by  means  of  the  bil- 
lions of  spores  produced.  This  development  of  summer 
spores  begins  soon  after  the  mycelium  gets  well  started, 
often-  before  the  whole  leaf  is  affected.  Many  of  these 
spores  are  likely  to  be  washed  through  the  soil  till  they 
reach  the  tubers,  and  they  may  develop  there,  causing  a 
characteristic  brown  discoloration. 

This  fungus  commonly  passes  the  winter  by  means  of 


SPORES  ON  LEAF.  Magni- 
fied :  a,  spore ;  b,  spore 
germinating;  c,  spore 
with  germinating  tube 
entering  breathing  pore 


222  FARM   FRIENDS   AND   FARM   FOES 

the  mycelium  in  the  diseased  potatoes.  When  they  are 
planted,  a  new  crop  of  spores  apparently  is  produced, 
either  on  the  seed  potato  itself  or  upon  the  stalks  and 
leaves  that  grow  from  it.  Many  of  the  downy  mildews 
have  special  winter  spores  by  means  of  which  the  fungus 
lives  from  one  season  to  another,  but  these  seem  not  to 
have  yet  been  certainly  found  in  this  species  affecting  the 
potato. 

The  best  methods  of  controlling  Potato  Blight  are  the 
planting  of  tubers  from  fields  in  which  the  disease  was  not 
present,  spraying  with  Bordeaux  mixture,  rotation  of  the 
crop,  and  the  selection  of  resistant  varieties. 

When  a  parasitic  fungus  attacks  one  plant,  it  is  very 
likely  to  attack  other  closely  related  plants.  The  tomato 
is  closely  related  to  the  potato.  Consequently  it  does  not 
seem  strange  that  there  is  a  Tomato  Blight  caused  by 
the  same  fungus  that  causes  the  Potato  Blight.  It  is 
often  destructive  in  wet  summers  in  the  Eastern  states  and 
during  damp  winters  in  southern  California.  Rotation  of 
crops  and  spraying  with  Bordeaux  mixture  are  effective 
preventive  measures. 

OTHER  DOWNY  MILDEWS 

A  parasite  closely  related  to  the  Downy  Mildew  of 
potatoes  is  the  Downy  Mildew  of  Lima  Beans.  This  at 
times  is  very  destructive  in  many  parts  of  the  United 
States,  sometimes  greatly  reducing  or  almost  destroying 
the  crop.  It  appears  as  a  thick  white  covering  upon  the 
pods,  injuring  the  tissues  of  the  wall  and  often  extending 
the  damage  to  the  young  beans  inside.  It  spreads  chiefly 
by  means  of  summer  spores,  and  apparently  passes  the 
winter  in  the  seed  in  the  form  both  of  dormant  mycelium 
and  of  distinct  winter  spores. 


THE  DOWNY   MILDEWS  223 

The  chief  preventive  measures  are  the  planting  on  high 
land  of  seed  gathered  from  a  field  where  the  mildew  was 
not  present,  the  rotation  of  the  crop,  the  destruction  of  all 
old  bean  vines,  and  spraying  with  Bordeaux  mixture. 

The  Downy  Mildew  of  the  Onion  is  a  widely  distributed 
disease  that  causes  serious  loss  in  some  parts  of  the 
United  States  nearly  every  year.  It  attacks  the  leaves, 
at  first  causing  a  yellowish  discoloration  that  may  later 
show  the  white  threads  of  the  fruiting  fungus.  Vast 
numbers  of  summer  spores  enable  the  disease  to  spread 
rapidly  during  the  growing  season,  and  well  protected 
winter  spores  enable  it  to  live  through  the  winter  in  dead 
leaves  or  in  the  soil.  These  winter  spores  appear  to  be 
able  to  survive  in  the  soil  for  two  years.  Consequently  a 
crop  rotation  in  which  onions  are  not  grown  on  the  same 
land  oftener  than  once  in  three  years  is  desirable.  Clean 
culture,  burning  of  diseased  leaves,  and  spraying  with 
fungicides  are  also  helpful. 

Another  Downy  Mildew  is  often  destructive  to  cucum- 
bers, melons,  and  squashes.  It  is  likely  to  destroy  the  vines 
in  almost  any  region  when  warm  damp  weather  favors  its 
rapid  growth.  It  seems  to  do  as  much  damage  in  the  South 
as  in  the  North,  or  more,  and  it  often  appears  as  an  active 
epidemic  quickly  blighting  the  vines  over  great  regions. 
The  white  mildew  that  gives  off  millions  of  summer  spores 
shows  on  the  under  surfaces  of  the  leaves. 

Clean  culture,  burning  or  deep  burying  of  infested  plants, 
rotation  of  crops,  and  spraying  with  fungicides  are  the  chief 
remedial  measures  against  this  disease. 

Among  the  numerous  parasitic  enemies  of  the  grape  the 
Downy  Mildew  or  Brown  Rot  is  at  times  one  of  the  most 
destructive.  In  its  life  history  it  does  not  differ  essentially 
from  the  other  Downy  Mildews.  It  reproduces  in  summer 


224  FARM   FRIENDS   AND   FARM   FOES 

by  summer  spores  and  passes  the  winter  in  the  form  of 
winter  spores.  It  attacks  leaves,  young  stems,  and  green 
fruits,  causing  a  mildew-like  growth  on  the  former  and  a 
brown  rot  of  the  latter.  It  is  prevented  by  spraying  with 
Bordeaux  mixture. 

The  Brown  Rot  of  the  Lemon  has  recently  become  a 
destructive  disease  in  California.  The  fungus  attacks  the 
rind -of  the  lemon,  causing  a  brownish  discoloration  and  a 
characteristic  odor.  It  is  likely  to  spread  through  the  fruit 
of  boxes  in  storage  or  in  transit,  so  that  it  often  causes 
serious  and  unexpected  losses.  The  spores  are  produced 
on  the  ground  and  not  on  the  lemons,  but  they  often  reach 
the  latter  through  the  water  in  which  the  fruit  is  washed. 
Consequently,  one  desirable  measure  of  control  is  the  disin- 
fection of  this  water  by  the  addition  of  a  small  amount  of 
formalin  or  some  other  germicide.  Full  details  of  treat- 
ment may  be  found  in  the  bulletins  of  the  California  Experi- 
ment Station. 


OBSERVATIONS   FOR   PUPILS 
MUSHROOMS 

1.  Bring  in  a  fresh  mushroom  or  toadstool.     Compare  it  with  the 
picture  on  page  215.     Do  you  see  all  the  parts  there  represented? 

2.  Place  a  fresh  mushroom  upon  a  sheet  of  paper  and  leave  over 
night.     See  if  there  are  spores  on  the  paper  in  the  morning.     If  so,  ex- 
amine under  a  microscope. 

3.  Dig  up  the  soil  at  the  base  of  the  stem  of  a  mushroom  to  see  if 
you  can  find  the  mycelium  from  which  it  developed. 

4.  Look  in  lawns  and  pastures  to  see  the  "fairy  rings  "  of  mushrooms 
that  so  often  occur.     See  if  you  can  find  out  the  explanation  of  the  pro- 
duction of  such  rings. 

5.  Draw  a  mushroom  an^d  label  the  parts. 


THE  DOWNY   MILDEWS  225 

DOWNY  MILDEWS 

1.  Which  of  these  diseases  have  you  known  to  be  present  in  your 
neighborhood  ? 

Downy  Mildew  or  Late  Blight  of  the  Potato. 

Downy  Mildew  of  the  Tomato. 

Downy  Mildew  of  the  Lima  Bean. 

Downy  Mildew  of  the  Onion. 

Downy  Mildew  of  Cucurbits. 

Downy  Mildew  or  Brown  Rot  of  the  Grape. 

2.  What  preventive  measures  are  used  against  these  diseases  in  your 
neighborhood? 

3.  Make  sketches  of  leaves  affected  by  the  disease  in  the  case  of  such 
of  these  as  you  find. 

4-    Read  Fanners' Bulletin  91. 


CHAPTER  XX 


The  Smut  Fungi 

THE  Smuts  form  a  distinctive  group  of  parasitic  plants 
called  by  botanists  Ustilaginales.  The  mycelium  develops 
in  the  tissues  of  the  host  plant  and  causes  serious  injury  to 
the  parts  infested.  Spores  are  developed  in  the  form  of 
the  blackish  powder  so  characteristic  of  Corn  Smut  and 
Oats  Smut.  These  primary  spores  germinate  under  favor- 
able conditions  and  often  bring  about 
the  development  of  enormous  numbers 
of  secondary  spores. 

Nearly  every  one  is  familiar  with  the 
Loose  Smut  disease  which  so  often 
affects  the  heads  of  oats,  causing  them 
to  become  masses  of  loose  blackish 
powder  instead  of  healthy  kernels  of 
grain.  These  black  powdery  masses 
are  composed  of  millions  of  the  minute 
spores  by  means  of  which  the  fungus 
multiplies. 

These  spores  appear  on  the  plants  when  the  oats  in  the 
field  are  blossoming.  At  that  time  the  seed  envelopes  — • 
which  later  form  the  "  chaff  "  —  are  spread  apart,  so  that  it 
is  easy  for  the  spores  to  lodge  inside  them.  There  the  spores 
remain,  even  through  the  threshing  process. 

The  spores  that  have  thus  been  concealed  beneath  the 
chaff  remain  in  position  until  the  grain  is  planted.  The 
moisture  and  warmth  favorable  to  the  starting  of  the  seed 

226 


SMUT  SPORIDIA 
Magnified 


THE   SMUT  FUNGI 


227 


also  cause  these  spores  to  germinate.  They  send  out 
tiny  tubes  that  penetrate  the  young  oats  plant.  The  threads 
of  the  fungus  thus  get  into  the  growing  tissues  where  they 
continue  to  develop  by  sending  out  numerous  branches  that 
run  through  all  parts  of  the  stalk.  An  elaborate  mycelium 
is  thus  formed,  and  continues  to 
develop  along  with  the  growing 
oats  plant. 

When  the  grain  begins  to  send 
out  its  heads,  the  fungus  develops 
a  mass  of  thickened  threads  within 
the  florets.  These  threads  soon 
give  rise  to  millions  of  blackish 
spores  that  form  the  familiar  pow- 
der of  smutted  grain. 

The  spores  of  this  fungus  are  so 
minute  that  the  number  in  a  single 
diseased  oats  head  is  almost  incon- 
ceivably great.  It  has  been  esti- 
mated that  a  single  cubic  inch  of 
the  smut  powder  would  contain 
64,000,000,000  spores.  Of  course, 
most  of  these  spores  never  develop. 
With  the  lower  forms  of  life,  Nature  produces  vast  numbers 
of  reproductive  bodies,  with  the  expectation,  as  it  were, 
that  only  a  small  fraction  of  a  per  cent  will  find  conditions 
suitable  for  continued  existence. 

Many  experiments  have  shown  that  Oats  Smut  may  be 
prevented  by  soaking  the  seed  in  diluted  solutions  of  for- 
malin, thus  destroying  the  spores  that  cause  the  disease. 

There  is  another  form  of  smut  disease,  which  is  more  in- 
jurious to  wheat  than  this  loose  smut,  called  the  Bunt  or  Ill- 
smelling  Smut,  because  it  has  a  distinctly  disagreeable  odor. 


OATS 
SMUT 


228  FARM   FRIENDS   AND   FARM   FOES 

With  this  malady  the  individual  kernels  of  wheat  are  affected 
rather  than  the  whole  head.  Such  kernels  appear  whitish 
or  bleached  in  contrast  to  the  yellow  of  the  healthy  grains. 

CORN  SMUT  AND  ONION  SMUT 

The  curiously  swollen  kernels  on  ears  of  Indian  corn 
affected  by  the  Smut  are  probably  familiar  to  every  boy  or 
girl  brought  up  in  the  country.  The  swelling  is  due  to  the 
growth  of  a  parasitic  fungus  that  develops  among  the  grow- 
ing tissues,  making  the  plant  cells  abnormal  and  finally 
destroying  them.  In  place  of  cells  of  healthy  tissue  enor- 
mous numbers  of  tiny  blackish  spores  are  finally  produced. 
These  are  the  reproductive  portions  of  the  parasitic  fungus. 
These  blackish  spores  are  so  fine  and  light  that  they  are 
readily  scattered  by  the  wind  or  are  easily  floated  from  place 

to  place  by  running  water  at 
times  of  rain  or  flood.  Un- 
der favorable  conditions  as 
to  warmth  and  moisture  each 
spore  is  able  to  germinate 
and  produce  other  or  second- 
CORN  SMUT  ary  spores,  which  in  turn  are 

able  to  penetrate  the  tissues 
of  the  young  corn  plant  and  start  the  disease  anew. 

The  greatest  injury  by  Corn  Smut  occurs  in  gardens 
where  corn  is  grown  season  after  season  and  the  smutted 
ears  are  left  upon  the  soil.  The  first  step  in  prevention  is 
to  destroy  promptly  all  the  parts  of  corn  plants  that  are 
producing  the  disease,  thus  checking  the  development  and 
dispersal  of  the  spores.  Rotation  of  crops  is  also  helpful. 
The  sorts  of  Smuts  with  which  most  people  are  familiar 
are  those  affecting  grains  in  which  the  fruiting  kernels  show 


THE   SMUT   FUNGI  229 

the  injury  most  plainly.  Some  parasitic  fungi,  however, 
develop  upon  the  leaves  and  stems  of  other  plants.  The 
Onion  Smut  is  one  of  the  most  important  of  these.  It  attacks 
the  leaves  and  bulbs  of  seedling  onions,  giving  them  a  char- 
acteristic blackish  appearance,  and  often  ruining  the  crop. 
The  spores  develop  secondary  spores  called  sporidia  in 
much  the  same  way  that  other  Smut  diseases  develop. 

The  Onion  Smut  is  especially  troublesome  on  land  in 
which  successive  crops  of  onions  are  grown.  This  is  be- 
lieved to  be  due  to  the  presence  of  the  spores  in  the  soil. 
Consequently,  a  wise  crop  rotation  is  the  first  preventive 
measure.  The  spores  are  also  easily  carried  from  field  to 
field  in  the  soil  adhering  to  hoes  or  other  tools.  Conse- 
quently, care  should  be  taken  to  prevent  this,  as  well  as  to 
prevent  the  washing  of  the  spores  from  field  to  field.  Clean 
culture  and  the  deep  burying  or  burning  of  all  infested 
plants  is  desirable. 

The  Smut  fungus  apparently  enters  the  seedling  onions 
about  the  time  they  come  up,  rather  than  later.  Conse- 
quently, onions  started  in  special  beds  and  transplanted  are 
seldom  injured. 

OBSERVATIONS   FOR   PUPILS 
LOOSE  SMUT  OF  OATS 

1.  Have  you  seen  smutted  oats  heads  in  fields?     How  much  damage 
does  the  disease  do  in  your  neighborhood? 

2.  If  there  is  a  compound  microscope  in  school,  examine  the  spores 
under  a  high  power. 

3.  Bring  in  a  diseased  oats  head  which  has  not  yet  burst  open  ;  place 
the  stem  in  a  bottle  of  water  and  watc^  it  for  a  few  days  to  see  the  pro- 
duction of  spores. 

4.  Make  a  sketch  of  a  panicle  of  oats  injured  by  Loose  Smut. 

5.  Read  Farmers'  Bulletin  250. 


230  FARM   FRIENDS   AND   FARM   FOES 

CORN  SMUT 

1.  In  your  neighborhood,  is  Corn  Smut  more  injurious  to  sweet  corn 
than  to  field  corn  ?     Is  it  more  destructive  in  gardens  where  sweet  corn 
is  planted  in  the  same  place  year  after  year  than  in  gardens  where  the 
sweet  corn  is  rotated  with  other  crops? 

2.  At  what  time  do  the  first  black  spores  develop  on  the  smutted 
ears  ? 

3.  Do  the  people  of  your  locality  take  pains  to  cut  out  and  burn  the 
diseased  plants  ? 

4.  Make  a  drawing  of  a  diseased  ear  of  corn.     If  there  is  a  com- 
pound microscope  in  school,  make  sketches  of  the  spores  as  seen  with  a 
high-power  objective. 


CHAPTER   XXI 
The  Rusts  (Uredinales) 

FEW  fungous  diseases  are  more  widespread  in  the  United 
States  or  more  readily  found  in  any  locality  than  the  As- 
paragus Rust.  This  fungus  was  described  in  Europe  in 
1805  and  had  doubtless  existed  for  ages  before  that  time. 
As  a  serious  enemy  it  first  attracted  attention  in  the  East- 
ern states  in  1896.  It  spread  westward  so  rapidly  that  in 
1901  it  was  very  destructive  in  California.  Since  then  it 
has  been  generally  recognized  as  the  worst  obstacle  to  as- 
paragus culture. 

In  a  way  the  life  history  of  this  rust  is  typical  of  the 
great  family  to  which  it  belongs.  It  passes  through  the 
winter  in  characteristic  spores  attached  to  old  leaves  and 
stalks,  or  lying  loose  upon  the  soil  surface.  These  are 
called  the  Winter  Spores  or  teleutospores.  They  are 
stalked,  double-celled  spores  of  curious  and  characteristic 
form. 

In  spring  these  teleutospores  germinate  as  they  lie  upon 
the  ground  or  upon  the  standing  or  fallen  asparagus  stalks. 
The  contents  of  each  cell  break  through  the  cell  wall  and 
run  out  in  the  form  of  a  long  tube.  At  the  end  of  the 
tube  four  partitions  develop,  so  that  four  distinct  cells  are 
formed.  Then  the  material  in  each  cell  is  sent  out  to  form 
a  tiny  secondary  spore  or  sporidium  (plural  sporidia}. 

These  sporidia  are  so  small  and  light  that  they  are  easily 
blown  about  by  the  wind.  When  one  of  them  chances  to 
alight  upon  the  green  surface  of  a  young  asparagus  plant 

231 


232 


FARM   FRIENDS   AND    FARM   FOES 


wet  with  dew  or  rain,  it  sends  out  a  germinating  tube  that 
penetrates  the  outer  skin,  generally  through  a  breathing 
pore,  and  starts  a  growth  of  fungus  threads  or  mycelium 
inside.  These  threads  continue  to  grow  and  push  in  be- 
tween the  green  cells  of  the  leaf  or  stem,  absorbing  nourish- 
ment from  them. 

After  a  short  time  the  early  spring  mycelium  has  absorbed 
so  much  material  from  the  green  cells  that  it  is  able  to  de- 
velop a  new  set  of  spores.  A  special  growth  of  the  fungus 
threads,  occurs  at  certain  places  just  below  the  outer  skin, 


SPORE  GERMINATING  WITH  TUBE 
ENTERING     Sl'OMATA;      SEEN 

FROM  ABOVE 


GERMINATING  TUBE  AMONG 
CELLS  OF  LEAF;  SEEN  FROM 
SIDE 


which  becomes  swollen  with  light  green  spots.  Soon  the 
skin  breaks  apart  and  the  fungus  threads  produce  great 
numbers  of  small  round  spores.  The  small  swollen  places 
where  these  spores  are  produced  are  called  (Ecidia  (singular, 
cecidium\  and  the  spores  produced  in  them  are  called  (zcid- 
ial  spores  or  spring  spores,  because  they  develop  in  spring. 
These  spring  spores  are  scattered  broadcast  by  the  wind. 
When  one  of  them  chances  to  alight  upon  the  green  surface 
of  a  moist  asparagus  plant,  it  sends  out  a  germinating  tube 
that  penetrates  the  tissues  in  much  the  same  way  that  the 
germinating  tube  of  the  sporidium  did  at  the  beginning  of 
the  season.  On  the  inside  the  germinating  tube  continues 
to  grow,  forming  new  fungus  threads  that  absorb  the  life 


THE  RUSTS  233 

substance  of  the  previously  healthy  cells.  After  a  time 
this  mycelium  is  ready  to  produce  spores  again,  and  it 
causes  more  tiny  swellings  upon  the  green  surfaces  of  leaves 
and  stems.  The  skin  of  the  swollen  dots  soon  breaks  apart, 
revealing  swarms  of  tiny  rust-colored  spores.  These  are 
the  uredospores  or  summer  spores.  They  give  the  famil- 
iar rusty  color  to  diseased  asparagus  plants.  They  are  pro- 
duced in  untold  billions,  to  be  scattered  by  the  wind  from 
plant  to  plant  and  from  field  to  field. 

When  they  alight  under  conditions  .  favorable  to  growth, 
they  start  the  disease  anew.  These  summer  spores  are  the 
chief  means  for  the  general  dispersal  of  the  rust.  Like 
the  spores  produced  in  spring,  they  are  unable  to  survive 
long  in  a  condition  to  germinate. 

As  autumn  comes  on,  if  the  asparagus  host  plant  becomes 
weakened  from  any  cause,  the  mycelium  in  the  leaves  and 
stems  produces  yet  a  third  kind  of  spores  —  the  black  rust  or 
winter  spores  with  which  our  little  story  began.  These 
are  called  teleutospores  :  they  develop  in  great  numbers  in 
swollen  pustules,  their  black  color  giving  this  stage  the 
name  black  rust  to  distinguish  it  from  the  orange  rust  of  the 
uredospore  stage. 

These  two-celled  teleutospores  have  comparatively  thick 
walls  which  enable  them  to  survive  the  winter  and  start 
the  disease  anew  in  the  spring. 

To  summarize  this  story  of  the  yearly  cycle  of  the  As- 
paragus Rust:  — 

1.  It  winters  in  the  black  rust  or  teleutospore  stage. 

2.  In  spring  the  teleutospores  germinate  into  secondary 

spores  called  sporidia. 

3.  These  sporidia  infect  asparagus  plants  and  start  in 

the  tissues  of  leaf  and  stem  a  growth  of  fungus 
threads  or  mycelium. 


234  FARM  FRIENDS  AND   FARM  FOES 

4.  This   mycelium  soon   produces  certain  swellings  or 

pustules  called  aecidia  from  which  spring  spores  or 
aecidiospores  are  developed. 

5.  These  aecidiospores  spread  the  disease  and  start  more 

mycelium. 

6.  In   summer  the   mycelium  produces  other  pustules 

from  which  the  orange-colored  summer  spores  or 
uredospores  are  developed. 

7.  These  uredospores  spread  the  disease  far  and  wide, 

starting  more  mycelium  from  which  more  uredo- 
spores are  developed. 

8.  In  autumn  the  mycelium  in  the  tissues  produces  black 

pustules  from  which  the  winter  spores  or  teleuto- 
spores  are  developed,  thus  completing  the  yearly 
cycle. 

Even  in  a  slightly  infested  asparagus  field  there  are  mil- 
lions of  teleutospores  each  spring.  If  each  of  these  devel- 
ops eight  sporidia,  there  are  of  course  enormous  numbers  of 
the  latter  produced.  These  sporidia  are  short-lived,  how- 
ever, and  each  must  soon  find  a  living  asparagus  plant  if  it 
is  to  start  the  disease  anew.  In  established  fields  the 
asparagus  is  cut  and  carried  off  almost  as  soon  as  it  comes 
up.  Consequently,  there  is  little  chance  for  the  rust  to  get 
a  foothold  there.  The  asparagus  plants  upon  which  the 
disease  grows  in  spring  are  generally  chance  seedlings  in 
neglected  corners  or  those  newly  planted  fields  in  which 
cutting  has  not  been  begun.  It  is  important,  therefore,  to 
destroy  wild  asparagus  plants,  for  they  help  to  tide  the 
disease  over  the  weeks  of  spring. 

CLOVER  RUST 

The  Clover  Rust  is  similar  in  its  yearly  history  to  the 
Asparagus  Rust.  It  has  the  same  three  kinds  of  spores 


THE  RUSTS  235 

succeeding  one  another,  and  is  found  upon  both  red  and 
white  clovers.  It  is  a  widespread  disease,  but  seldom  does 
serious  injury. 

Another  closely  related  fungus  is  Alfalfa  Rust,  but  this 
as  a  rule  causes  only  a  minor  injury.  The  pustules  showing 
the  summer  spores  are  likely  to  be  found  upon  alf alf a  leaves 
at  any  time  in  summer. 

The  Rose  Rust  is  still  another  species  having  a  life  story 
similar  to  that  of  the  Asparagus  Rust.  It  is  very  frequently 
found  upon  the  leaves  and  stems  of  roses.  Other  rusts 
occasionally  occur  upon  beans  and  beets. 

WHEAT  STEM  RUST 

The  Asparagus  Rust  is  typical  of  the  rusts  that  pass  their 
various  stages  upon  one  host.  There  are  many  others,  how- 
ever, in  which  the  fungus  develops  part  of  the  year  upon 
another  host,  so  that  the  life  history  may  seem  even  more 
complex  than  that  of  the  Asparagus  Rust. 

The  Stem  Rust  of  Wheat  is  a  good  example  of  a  rust  that 
lives  upon  two  hosts.  Most  people  in  regions  where  wheat 
is  grown  are  familiar  with  the  slender  black  spots  on  the 
leaves  and  stems  of  ripened  wheat.  Under  a  lens  these  are 
readily  seen  to  consist  of  teleutospores,  similar  to  the  teleu- 
tospores  of  the  Asparagus  Rust.  They  serve  as  the  winter 
spores  of  the  Wheat  Stem  Rust,  living  through  the  winter 
wherever  the  straws  may  be. 

In  spring  the  teleutospores  germinate  by  sending  out 
tubes,  and  these  tubes  in  turn  give  rise  to  secondary  spores 
called  sporidia  exactly  as  in  the  case  of  the  Asparagus  Rust. 

These  sporidia  are  blown  about  by  the  wind.  If  one 
chances  to  light  upon  a  moist  barberry  leaf,  it  germinates 
and  sends  its  fungus  thread  through  a  breathing  pore  into 


236  FARM   FRIENDS  AND   FARM   FOES 

the  tissues  of  the  leaf.  Here  it  develops  into  a  mycelium 
that  soon  produces  swollen  orange-colored  pustules,  often 
called  cluster  cups.  In  these  pustules  the  mycelium 
'develops  aecidiospores  or  spring  spores  which  in  turn  are 
blown  through  the  air  by  the  wind.  This  is  often  called 
the  cluster-cup  stage  of  the  rust. 

Some  of  the  aecidio  spores  are  likely  to  find  lodgment 
upon  the  leaves  or  stalks  of  wheat  plants.  When  moisture 
from  dew  or  rain  is  present,  these  will  germinate  and  start 
a  growth  of  mycelium  in  the  tissues.  This  mycelium  will 
soon  produce  a  crop  of  rust-colored  uredospores  or  summer 
spores  which  scatter  through  the  wheat  fields  and  spread 
the  disease  rapidly.  This  process  continues  through  most 
of  the  summer,  and  consequently  this  is  the  stage  in  which 
the  most  damage  is  done  by  the  rust  fungus. 

Finally,  as  the  wheat  matures  the  mycelium  in  the  tissues 
gives  rise  to  the  black  rust  or  teleutospore  stage.  In  this 
condition  it  passes  the  winter. 

YEARLY  CYCLE  OF  WHEAT  STEM  RUST 

I.   Early  Spring. 

a.   Teleutospores  develop  sporidia. 
b.   Sporidia  are  blown  to  barberry. 

c.   Sporidia  develop  mycelium  in  barberry  leaf. 
II.   Late  Spring. 

d.   Mycelium  in  barberry  leaf  develops  aecidiospores. 
e.   yEcidiospores  are  blown  to  wheat. 

f.   ^Ecidiospores  develop  mycelium  in  wheat. 

III.  Summer. 

g.   Mycelium  in  wheat  develops  uredospores. 

h.   Uredospores  are  blown  to  other  wheat  plants. 

/.   Uredospores  develop  mycelium  in  these  wheat  plants. 

IV.  Autumn. 

j.   Mycelium  in  these  wheat  plants  develop  teleutospores  that 
live  through  the  winter. 


THE  RUSTS  237 

If  you  will  compare  this  yearly  history  of  the  wheat  rust 
with  that  of  the  asparagus  rust,  you  will  see  that  the  chief 
difference  is  that  the  sporidia  develop  upon  another  host 
from  which  the  aecidiospores  return  to  the  wheat  plant. 
This  difference  is  typical  of  many  other  rust  fungi,  and 
special  names  are  given  to  indicate  the  group  to  which  the 
various  sorts  belong:  — 

When  the  different  stages  of  a  rust  fungus  develop  on 
one  kind  of  plant,  it  is  said  to  be  an  autcecious  species ;  ex- 
ample, the  Asparagus  Rust. 

When  the  different  stages  of  a  rust  fungus  develop  upon 
two  or  more  kinds  of  plants,  it  is  said  to  be  a  hetercecious 
species ;  example,  the  Wheat  Stem  Rust. 

The  stem-rust  on  wheat  and  barberry  is  the  typical  ex- 
ample of  a  heteroecious  rust.  It  is  interesting  because  of 
the  alternation  of  host  plants  and  because  all  three  forms 
of  spores  are  present.  The  Black  Stem  Rust,  however, 
often  occurs  in  regions  where  barberries  are  either  rare  or 
not  found  at  all,  and  there  is  no  doubt  that  the  fungus  can 
live  from  year  to  year  without  going  through  the  cluster- 
cup  stage  on  barberry. 


OTHER  GRAIN  RUSTS 

There  are  other  rusts  of  grain  even  more  destructive 
than  the  Wheat  Stem  Rust.  The  Orange  Leaf  Rust  of 
Wheat  is  perhaps  the  worst  of  these.  Technically  it  is 
called  Puccinia  rubigo-vera.  It  is  believed  by  good  au- 
thorities to  be  the  most  abundant  of  all  grain  rusts  in  the 
United  States.  The  uredospore  form  is  the  one  generally 
present,  and  in  the  South  at  least  the  fungus  can  live 
through  the  year  with  no  other  spores  present.  Teleuto- 
spores  have  been  found,  but  the  aecidium  stage  is  unknown. 


238  FARM  FRIENDS  AND   FARM   FOES 

The  Crown  Rust  or  Orange  Leaf  Rust  of  oats  is  an 
abundant  and  widespread  disease.  Technically  it  is  known 
as  Puccinia  coronata.  It  has  a  life  history  very  simi- 
lar to  that  of  the  Black  Stem  Rust,  the  spring  spores  or 
aecidiospores  being  developed  upon  buckthorn  instead  of 
barberry.  There  seems  little  doubt,  however,  that  the 
fungus  can  pass  through  the  year  in  the  absence  of  this 
aecidium  stage. 

Serious  injury  by  the  Rust  of  Indian  Corn  is  only  rarely 
reported,  although  the  fungus  is  very  common.  It  appears 
on  the  leaves  in  brownish  pustules  of  uredospores  that 
develop  during  summer.  They  are  followed  later  in  the 
season  by  blackish  teleutospores  which  live  over  winter 
to  start  the  disease  anew  in  spring.  This  fungus  is  known 
as  Puccinia  Sorghi. 


CEDAR  AND  APPLE  RUST 

Another  good  example  of  a  heteroecious  rust  is  the  one 
that  causes  the  "cedar  apples"  so  often  found  on  cedar 
trees.  These  are  curious  little  orange-colored  balls  that 
occur  along  the  twigs.  In  autumn  and  winter  they  have 
smooth,  rounded  surfaces,  but  in  spring  they  send  out  curi- 
ous jelly-like  masses  about  half  an  inch  long.  The  teleu- 
tospores germinate  by  sending  out  tubes  that  give  rise  to 
secondary  spores  or  sporidia.  These  sporidia  are  blown 
about  by  the  wind :  such  as  fall  on  moist  leaves  of  apple, 
quince,  or  June-berry  are  likely  to  germinate  and  start  a 
growth  of  mycelium  within  the  leaf. 

This  mycelium  soon  gives  rise  to  swollen  pustules  called 
cluster  cups  or  aecidia.  In  these  millions  of  brownish 
aecidiospores  are  developed.  These  are  blown  about  by 
the  wind,  and  such  of  them  as  chance  to  light  upon  moist 


THE  RUSTS  239 

cedar  branches  germinate  and  start  a  growth  of  mycelium 
in  them.  There  appear  to  be  no  uredospores  and  no 
spreading  of  the  disease  to  other  apple  trees  by  the  aecidio- 
spores. 

Consequently,  in  this  case  of  the  Cedar  Apple  and  Apple 
Rust  we  have  but  two  distinct  forms  instead  of  the  three 
in  the  case  of  the  Black  Stem  Rust. 

Thus:  — 

1 .  Cedar  Apples  on  Cedar. 

Teleutospores  develop  sporidia  to  go  to  apple  leaves. 

2.  Apple  Rust. 

A.  Sporidia   cause  mycelium   that  produces  aecidia 
containing  aecidiospores. 

B.  ^Ecidiospores  go  to  cedar  trees  to  develop  cedar 
apples. 

The  mycelium  in  the  cedar  trees  is  perennial,  living 
from  year  to  year  and  producing  each  season  new  cedar 
apples  to  send  out  sporidia.  Consequently,  the  destruction 
of  the  cedar  trees  is  helpful  in  preventing  the  development 
of  the  Apple  Rust. 

OTHER  RUSTS 

The  Orange  Rust  of  blackberries,  dewberries,  and  rasp- 
berries is  one  of  the  most  conspicuous  and  widespread 
members  of  the  family.  It  affects  both  wild  and  cultivated 
plants  and  is  found  wherever  these  fruits  grow.  The  con- 
spicuous orange-colored  aecidiospores  appear  in  spring  and 
early  summer,  and  are  followed  later  by  a  crop  of  uredo- 
spores, and  these  in  turn  by  the  teleutospores.  The 
prompt  burning  of  all  infested  canes  is  very  desirable. 

A  characteristic  leaf  rust,  known  technically  as  Piiccinia 
Pruni,  commonly  affects  plums,  peach,  and  other  stone 


240  FARM   FRIENDS  AND   FARM   FOES 

fruits.  It  is  seldom  seriously  destructive.  The  only  spore- 
forms  known  are  the  summer  spores  and  the  teleutospores, 
both  being  of  the  brown  color  so  general  in  the  rusts. 

During  the  last  quarter  of  the  nineteenth  century  the 
Hollyhock  Rust  was  very  destructive  in  the  United  States. 
It  is  still  a  pest,  but  less  so  than  formerly  when  it  caused 
the  culture  of  hollyhocks  to  be  almost  abandoned.  There 
is  good  reason  to  hope  that  resistant  strains  of  Hollyhocks 
will  soon  be  developed. 

The  Hollyhock  Rust  appears .  as  brownish  pustules  on 
the  under  surface  of  the  leaves.  These  contain  an  abun- 
dance of  two-celled  teleutospores,  and  it  is  an  interesting 
fact  that  in  this  form  of  rust  fungus  this  seems  to  be  the 
only  form  of  spore  that  occurs.  The  teleutospores  are 
also  remarkable  for  their  ability  to  germinate  at  once  instead 
of  resting  through  the  winter  as  do  most  of  the  teleutospores. 
Consequently,  in  this  case  the  teleutospores  are  both  sum- 
mer spores  and  winter  spores.  The  gathering  and  burning 
of  affected  leaves  is  a  helpful  remedial  measure. 


OBSERVATIONS   FOR   PUPILS 
RUSTS 

1 .  Which  of  the  following  rusts  do  you  find  in  your  neighborhood  ?  — 

Apple  Rust  Hollyhock  Rust 

Asparagus  Rust  Oat  Crown  Rust 

Bean  Rust  Plum  Rust 

Beet  Rust  Raspberry  Rust 

Clover  Rust  Wheat  Leaf  Rust 

Corn  Rust  Wheat  Stem  Rust 

2.  Set  aside  a  page  of  your  booklet  for  three  of  the  most  important 
of  these  rusts,  and  write  a  brief  account  of  your  observations  upon  each. 


THE   RUSTS  241 

Perhaps  this  outline   will  help :  — 
The  name  of  the  disease. 

Its  abundance  and  the  amount  of  damage  it  does. 
The  parts  of  the  host  plant  most  affected. 
How  it  passes  the  winter. 
The  preventive  measures  used  against  it  in  your  neighborhood. 

3.  Press  a  few  leaves  or  stalks  showing  each  of  the  rusts  common  in 
your  locality.     Mount  them  on  pages  of  your  booklet. 

4.  Read  the  discussion  of  Grain  Rusts  in  Farmers1  Bulletin  219. 


CHAPTER   XXII 
The  Ascospore  and  Other  Fungi 

A  NUMBER  of  parasitic  fungi  are  classified  together  in  a 
group  called  Ascomycetes  because  the  principal  spores  are 
developed  in  special  tubular  spore  cases  called  asci ;  these 
spores  are  called  ascospores.  They  often  serve  as  a  means 
by  which  the  fungus  passes  through  the  winter ;  so  they 
are  sometimes  spoken  of  as  winter  spores.  The  fungus  may 
also  develop  more  temporary  spores  which  are  often  spoken 
of  as  conidiospores  or  summer  spores. 

BLACK  KNOT 

Most  schoolboys  have  seen  the  branches  of  plum  and 
cherry  trees  distorted  by  a  black,  knotty  growth,  having 
the  appearance  of  the  picture  on  the  opposite  page.  Wild 
cherry  trees  very  commonly  show  the  injury,  which  is  pro- 
duced by  the  fungous  disease  known  as  the  Black  Knot. 
The  knots  are  caused  by  the  growth  of  a  parasitic  fungus 
in  the  twigs  or  larger  branches.  They  first  appear  as 
swollen  places  on  the  bark.  These  enlarge  and  cause 
irregular  cracks  which  are  characteristic  of  the  disease. 
Finally  the  whole  circumference  of  the  twig  may  be  affected 
so  that  the  part  beyond  soon  dies. 

During  warm  weather  vast  numbers  of  summer  spores 
are  produced  upon  the  bark  of  the  knots.  These  give  the 
affected  part  of  the  twig  a  soft,  velvety  surface  of  a  dark 
olive  color.  These  spores  are  blown  from  place  to  place. 

242 


THE  ASCOSPORE  AND   OTHER  FUNGI 


243 


Those  that  fall  upon  green  and  tender  bark  are  likely  to 
germinate  and  start  the  disease  again. 

As  cold  weather  approaches,  the  tissues  of  the  outer  bark 
become  much  harder,  with  many  little  cavities  inside.  The 
fungus  produces  within  these  cavities 
spores  that  germinate  the  following 
spring  and  start  the  disease  anew. 

The  Black  Knot  affects  most  varie- 
ties of  plum  and  cherry  trees,  both 
wild  and  cultivated,  and  the  spores 
are  easily  carried  from  one  sort  of 
tree  to  another.  Consequently,  it  is 
important  that  in  any  locality  all 
traces  of  the  fungus  should  be  ex- 
terminated. The  cutting  down  of 
worthless  trees  and  the  pruning  away 
of  diseased  branches  are  the  first 
steps  in  the  control  of  Black  Knot. 

The   cutting   out  of   the  injury  as 
soon  as  it  appears  and  spraying  with  fungicides  will  also 
help  to  control  it. 

PEACH  LEAF  CURL 

Peach  Leaf  Curl  is  the  name  applied  to  a  malady 
that  often  affects  the  twigs  and  leaves  of  peach  trees.  It 
causes  the  leaves  to  swell  and  curl  soon  after  they  expand 
in  spring,  giving  them  an  abnormal  appearance  that  is  at 
once  recognized  as  due  to  a  diseased  condition.  The  threads 
of  the  fungus  penetrate  between  the  cells,  growing  rapidly 
and  causing  a  swelling  of  the  tissues.  The  injured  leaves 
fall  off  in  the  spring  or  early  summer.  The  twigs  affected 
also  become  swollen  and  distorted.  Sometimes  the  disease 
is  confined  to  a  branch  or  two,  but  frequently  it  involves 


BLACK  KNOT  ON  WILD 

CHERRY ;    WINTER 

CONDITION 


244  FARM   FRIENDS   AND   FARM   FOES 

the  foliage  of  the  whole  tree.  In  such  cases  the  young 
peaches  are  likely  to  drop  off,  and  the  crop  be  thus  de- 
stroyed. A  new  set  of  leaves  will  be  put  forth,  but  of  course 
the  tree  will  be  unable  to  produce  the  same  season  another 
crop  of  blossoms  and  young  fruit. 

Fortunately  this  disease  is  readily  prevented  by  spraying 
with  fungicides.  Winter  treatment  with  Bordeaux  mixture 
or  the  lime-sulphur  wash  is  an  effective  remedy.  This  is 
believed  to  be  due  to  the  fact  that  the  spores  of*  the  fungus 
pass  the  winter  chiefly  on  the  bark  and  buds  of  the  trees, 
so  that  they  are  killed  by  the  fungicide. 

PLUM  POCKETS 

The  Peach  Leaf  Curl  is  due  to  the  growth  of  a  parasitic 
fungus  that  belongs  to  the  genus  Exoascus.  The  fungi  of 
this  genus  cause  abnormal  growths  of  the  plants  they  in- 
fest. The  curious  "witches  brooms  "  often  seen  upon  birch 
and  other  trees  are  due  to  these  parasites.  So,  also,  are  the 
strangely  swollen  plums  often  seen  upon  the  plum  trees  and 
commonly  called  Plum  Pockets. 

Young  plums  are  generally  affected  by  the  Plum-pocket 
disease.  They  become  swollen,  and  when  cut  open  are 
seen  to  be  hollow,  with  no  pit.  After  a  time  they  are  likely 
to  be  covered  with  a  powder  composed  of  the  microscopic 
spores  of  the  fungus.  These  spores  are  widely  scattered 
by  wind  and  rain,  and  presumably  infest  other  trees,  though 
just  how  this  is  done  is  not  now  known. 

It  is  known,  however,  that  the  threads  of  the  fungus  live 
from  year  to  year  in  the  twigs  and  reach  the  young  fruits 
by  growing  through  the  blossom  or  fruit  stalks.  When  a 
branch  is  once  infested,  it  bears  the  Plum  Pockets  year  after 
year,  and  all  new  twigs  sent  out  by  it  beyond  the  point  of 


THE  ASCOSPORE  AND   OTHER  FUNGI 


245 


infection  do  likewise.  Consequently  it  is  evident  that  the 
threads  of  the  fungus  grow  along  with  the  new  growth  of 
the  branch.  The  best  remedy  is  to  cut  the  branch  off,  some- 
what below  the  point  of  infection,  thus  removing  the  dis- 
eased tissues. 

APPLE  SCAB  AND  PEAR  SCAB 

The  Apple  Scab  is  one  of  the  most  familiar  fungous 
diseases.  It  appears  as  black  spots,  upon  the  surface  of  the 
apple,  and  also 
upon  the  leaves. 
The  spores  of 
the  fungus  that 
causes  the  dis- 
ease are  pro- 
duced in  great 
abundance  on 
these  blackened 
spots.  They  are 
scattered  far  and 
wide  by  wind  and 
rain.  Those  that 
lodge  upon  the  leaves  or  fruits  of  apple  trees  germinate 
during  moist  weather  by  sending  out  little  tubes  and  thus 
start  the  disease  anew. 

The  growing  portion  of  the  fungus  consists  of  brown- 
ish cells.  After  a  time  the  cells  multiply  and  push  out- 
ward, exposing  a  surface  in  which  the  small  oval  spores 
develop.  These  spores  live  through  the  winter  on  the 
bark,  twigs,  and  stored  apples,  as  well  as  on  the  fallen 
leaves  and  fruit. 

The  Apple  Scab  fungus  not  only  causes  the  apples  to 
appear  unsightly  and  injures  them  for  food,  but  it  also  pre- 


APPLE  SCAB 


246  FARM   FRIENDS  AND   FARM   FOES 

vents  them  from  growing  to  as  large  a  size  as  they  would 
if  not  affected.  The  extent  of  this  dwarfing  is  illustrated 
in  the  figure  below.  The  disease  may  be  prevented  by 
spraying  with  fungicides,  the  self-boiled  lime-sulphur  wash 
being  one  of  the  best  for  this  purpose. 


DWARFED   BY 
APPLE  SCAB 

A  closely  related  fungus  causes  the  Pear  Scab,  which  is 
often  destructive  to  certain  varieties  of  pears.  Its  life  his- 
tory and  control  are  practically  the  same  as  the  Apple 
Scab. 

BITTER  ROT  OF  APPLE 

This  disease  causes  losses  of  millions  of  dollars  in  the 
United  States  almost  every  year.  It  is  generally  noticed 
upon  the  fruit,  especially  as  it  approaches  full  size.  Small 
brownish  spots  may  be  seen  at  first ;  these  gradually  en- 
large and  commonly  spread  over  much  of  the  apple,  caus- 
ing it  to  fall.  Many  of  the  smaller  fruits,  however,  re- 
main upon  the  tree,  shriveling  to  a  mummified  condi- 
tion, in  which  they  may  hang  to  the  twigs  until  the  next 
spring. 

After  the  mycelium  of  the  fungus  has  been  growing  in 
the  fruit  tissues  for  a  time,  it  develops  upon  the  surface 
characteristic  blackish  pustules  in  which  great  numbers  of 


THE  ASCOSPORE  AND  OTHER  FUNGI 


247 


spores  are  produced.  These  are  scattered  by  wind  and  rain 
and  serve  to  spread  the  disease  to  new  fruits.  The  myce- 
lium gives  a  bitter  taste  to  the  parts  of  the  apple  near  the 
decayed  spot. 

This  fungus  is  also 
able  to  develop  upon 
the  bark  of  apple 
trees,  where  it  pro- 
duces dead  blotches 
called  cankers.  The 
fungus  apparently 
passes  the  winter  both 
in  these  cankers  and 
in  the  mummied  fruits, 
from  which  new  crops 
of  spores  are  pro- 
duced in  spring  or 
early  summer. 

The  destruction  of 
mummied  and  fallen 
fruits,  cutting  out  and 


APPLES  AFFECTED   BY  BITTER    ROT 


burning     all     canker 

spots,     and     spraying 

with  fungicides  are  the  means  by  which  this  disease  may 

be  controlled. 

BROWN  ROT  OF  STONE  FRUITS 

The  Brown  Rot  of  peaches,  plums,  and  cherries  is  one 
of  the  most  destructive  diseases  affecting  fruits.  It  is  the 
commonest  cause  of  the  rotting  of  peaches  or  plums  both 
upon  the  tree  before  or  during  ripening,  and  also  in  the 
baskets  after  picking.  Its  life  history  is  similar  to  that  of 
the  other  fungi  that  cause  plant  diseases.  The  tiny  spores 


248 


FARM   FRIENDS   AND    FARM   FOES 


BROWN  ROT  SPORES 

DEVELOPING 

Magnified 


blown  upon  the  damp  fruit  send  out  their  germinating 
tubes  into  the  tissues  where  they  grow,  branching  in  all 
directions.  These  branches  absorb  the  cell  contents.  In 
this  way  the  green  tissues  are  broken 
down,  the  light  green  color  is  turned 
to  brown,  and  the  so-called  rot  ap- 
pears. On  the  outside,  the  fruit  first 
turns  brown  in  one  or  two  places,  then 
more  and  more  of  the  surface  appears 
affected,  until  finally  the  whole  surface 
shows  the  injury. 

Soon  after  the  fruit  has  thus  be- 
come discolored,  it  is  likely  to  show 
a  curious  velvety  coating  —  more  or 
less  grayish  in  color  —  that  is  made 
up  of  millions  of  tiny  spores.  They 
are  produced  by  the  threads  of  mycelium  that  have  been 
developing  amid  the  tissues  of  the  fruit.  Under  the  micro- 
scope they  are  easily  seen  to  resemble  the  figures  below. 

These  spores  are  blown  everywhere 
by  the  wind  and  serve  to  spread  the 
disease  very  rapidly.  A  single  affected 
fruit  may  furnish  millions  of  spores  for 
the  wind  to  sow  broadcast  over  the 
surrounding  country. 

Unless  the  diseased  fruits  are  re- 
moved, many  of  them  remain  upon  the 
tree.  They  shrivel  slowly  into  dry 
and  mummied  fruits  inside  which  the 
threads  of  mycelium  develop  into 
blackish  bunches  that  correspond  in  a 
way  to  winter  spores  and  enable  the 
fungus  to  survive  the  winter,  and  to  produce  a  new  crop 


BROWN  ROT 
a,  spores ;    b,  spores  ger- 
minating; magnified 


THE  ASCOSPORE  AND   OTHER  FUNGI  249 

of  spores  in  spring.  These  are  likely  to  develop  in  the 
tissues  of  the  buds,  blossoms,  and  young  twigs,  often  caus- 
ing serious  damage. 

Sometimes  a  curious  mushroom  stage  of  the  fungus  de- 
velops in  connection  with  the  mummied  fruits  upon  the 
ground.  Great  numbers  of  tiny  mushroom-like  objects 
develop  from  the  mycelium.  In  these  the  winter  spores 
or  ascospores  are  produced.  Apparently  this  stage  is  not 
generally  present,  and  is  not  necessary  to  the  yearly  cycle 
of  the  fungus. 

Evidently  one  of  the  chief  preventive  measures  with 
this  disease  is  the  gathering  of  all  the  mummied  fruits  in 
winter.  By  doing  this,  by  thinning  the  fruit,  and  by  spray- 
ing with  self-boiled  lime-sulphur  wash,  most  of  the  injury 
may  be  avoided. 

PEAR  LEAF  BLIGHT 

The  foliage  of  pear  and  quince  trees  often  becomes 
spotted  with  brown  in  summer,  and  the  spotting  sometimes 
is  so  extensive  that  the  leaves  turn  brown  and  fall  off. 
When  this  occurs  over  the  whole  tree  and  is  not  at  first 
confined  to  a  single  branch,  it  is  generally  caused  by  a  fungus 
that  attacks  the  leaves  early  in  the  season  and  continues 
to  develop  until  the  end  of  summer,  causing  the  disease 
known  as  the  Pear  Leaf  Blight.  This  fungus  is  a  distinct 
species  of  parasitic  plant  which  at  first  causes  small  reddish 
spots  to  appear  upon  the  leaves.  These  spots  gradually 
grow  larger  and  turn  brown  and  often  cause  the  whole  leaf 
to  become  brown  and  dead.  The  fungus  also  develops 
upon  the  fruit,  causing  it  to  crack  open.  Fortunately  this 
disease  may  be  almost  entirely  prevented  by  spraying  with 
fungicides. 


250  FARM   FRIENDS   AND    FARM   FOES 

STRAWBERRY  LEAF  SPOT 

Every  one  who  grows  strawberries  has  noticed  the  brown 
or  reddish  spots  that  appear  upon  the  leaves,  especially 
late  in  summer.  These  are  due  to  a  fungous  disease  called 
the  Strawberry  Leaf  Spot.  When  the  spots  first  appear, 
they  may  be  seen  on  the  upper  side  of  the  leaf  as  small 
dots  of  a  purple  or  reddish  color.  They  grow  larger  from 
day  to  day;  the  central  portions  become  brown  in  color, 
while  the  margins  retain  their  purple  hue.  The  fungus 
threads  within  the  cells  of  the  leaf  generally  affect  a  cir- 
cular area,  but  frequently  two  or  more  centers  of  disease 
will  be  sufficiently  near  each  other  to  run  together  and 
produce  a  large  discolored  blotch.  Sometimes  practi- 
cally the  whole  leaf  will  be  destroyed.  The  effect  of  the 
disease  upon  the  plant  is  to  dwarf  its  growth  and  lessen 
the  fruit  crop  produced  the  succeeding  year. 

The  Strawberry  Leaf  Blight  may  be  prevented  to  a  con- 
siderable extent  by  spraying  with  the  Bordeaux  mixture. 
Of  course  this  cannot  be  applied  while  the  berries  are  on 
the  vines.  An  excellent  way  to  treat  fruiting  plantations 
is  to  mow  the  vines  after  the  berries  are  gathered,  and 
burn  the  ground  over  as  soon  as  the  leaves  are  dry.  This 
destroys  the  spores  of  the  fungus  and  a  new  crop  of  leaves 
will  soon  be  produced  comparatively  free  from  blight, 
especially  if  they  are  sprayed  once  with  the  Bordeaux 

mixture. 

The  most  successful  growers  of  strawberries  renew  their 
plantations  every  year,  as  they  find  it  easier  to  set  out  a 
new  bed  than  to  clean  out  an  old  one.  When  this  method 
is  adopted  it  is  seldom  necessary  to  spray  to  prevent  the 
Leaf  Spot. 


THE  ASCOSPORE  AND   OTHER  FUNGI  251 

BLACK  ROT  OF  GRAPES 

The  Black  Rot  of  grapes  is  one  of  the  most  destructive 
plant  diseases.  It  often  causes  the  loss  of  a  large  part  of 
the  crop  in  many  vineyard  regions  and  is  generally  recognized 
as  a  dangerous  enemy.  The  disease  is  caused  by  a  fungus 
that  passes  the  winter  in  mummied  grapes  and  is  believed 
to  start  in  spring  from  ascospores  developed  in  them.  It 
appears  in  spring  or  early  summer  on  young  leaves  and 
branches,  producing  a  brown  discoloration.  Later  it  shows 
on  the  green  grapes  as  brownish  spots  that  spread  over 
the  whole  surface,  finally  producing  a  blackened  fruit  that 
is  appropriately  described  as  affected  by  Black  Rot. 

On  the  surf  ace  of  these  diseased  grapes  enormous  numbers 
of  summer  spores  are  developed.  These  are  scattered 
through  the  vineyard  by  wind  and  rain.  Whenever  one 
rests  upon  a  moist  grape,  it  is  likely  to  start  a  new  disease 
spot.  In  this  way  the  disease  may  spread  very  rapidly 
and  cause  great  loss. 

Clean  culture  and  the  destruction  of  dried  grapes  that 
carry  the  fungus  through  the  winter  are  desirable  preven- 
tive measures.  Spraying  with  Bordeaux  mixture  has  re- 
peatedly been  shown  to  be  an  efficient  remedy. 

COTTON  WILT 

Among  the  numerous  enemies  of  cotton  that  have  be- 
come seriously  destructive  during  recent  years,  the  Wilt 
Disease  is  especially  notable.  It  occurs  over  a  large  part 
of  the  cotton-growing  region  in  the  Southern  states.  The 
affected  plants  are  commonly  stunted  in  their  growth  for 
some  time  before  they  finally  wilt  as  if  from  lack  of  water. 
This  is  in  fact  the  case,  because  the  channels  through 


252 


FARM   FRIENDS   AND    FARM   FOES 


which  the  water  reaches  the  leaves  are  clogged  by  the 
growth  of  the  parasitic  mycelium. 

The  careful  studies  of  several  botanists  show  that  the 
fungus  which  causes  the  disease  is  commonly  present  in  the 
soil  of  cotton  fields,  where  it  is  able  to  live  long  periods 
as  a  saprophyte  —  getting  the  materials  of  growth  from 
decaying  matter  in  the  soil.  When  cotton  is  planted,  how- 
ever, it  commonly  becomes  a  parasite  by  invading  the 
tissues  of  the  plants.  The  same  or  a  very  similar  fungus 
causes  a  wilt  disease  in  watermelons  and  in  the  cowpea. 

The  only  successful  method  of  preventing  this  disease 
now  known  is  that  of  planting  varieties  that  can  resist 
its  attack.  Much  progress  has  been  made  in  the  develop- 
ment of  such  varieties,  and  there  is  reason  to  believe  that 
still  greater  progress  will  be  made  in  the  near  future. 

THE  POWDERY  MILDEWS 

From  midsummer  until  autumn  one  can  find  curious 
whitish  patches  upon  the  leaves  of  a  great  variety  of  trees, 
shrubs,  and  herbaceous  plants.  In  some  cases  there  are 
but  small  spots  of  white  upon  the  green  background  of  the 
leaf  blade,  while  in  others  the  whole  surface  may  be  whit- 
ened and  more  or  less  powdery  in  appearance.  As  autumn 
approaches  tiny  brownish  or  blackish  spots  appear  upon 
the  whitened  part.  Such  whitened  leaves  are  very  com- 
mon upon  lilacs,  roses,  willows,  red  maples,  hardy  phloxes, 
and  many  other  plants.  They  are  especially  likely  to 
be  found  on  leaves  growing  in  the  shade.  Such  leaves 
are  probably  affected  by  some  form  of  those  parasitic 
fungi  called  Powdery  Mildews.  These  are  among  the  most 
characteristic  of  the  ascospore  fungi,  and  form  a  very  dis- 
tinctive family. 


THE   ASCOSPORE   AND   OTHER   FUNGI  253 

If  you  will  look  through  a  lens  or  the  lower  power  of  a 
compound  microscope  at  one  of  the  leaves  thus  affected, 
you  will  see  that  the  whitish  appearance  is  due  to  vast 
numbers  of  tiny  threads  that  run  over  the  surface  of  the. 
leaf,  interlacing  in  a  most  interesting  fashion.  You  will 
find  that  the  brownish  or  blackish  dots  are  well-developed 
spore  cases  —  technically  called  perithecia  —  often  having 
curious  projections  from  the  outer  wall.  You  can  probably 
see  these  cases  in  all  stages  of  growth,  from  the  young 
whitish  ones  to  the  mature  blackish  ones. 

If  you  place  a  few  of  the  well-developed  spore  cases  on 
a  glass  slide  in  water,  cover  with  another  piece  of  glass, 
arid  crush  the  walls,  you  will  see  the  spores  come  out. 
These  spores  are  inclosed  in  smaller  sacklike  cases  —  the 
asci. 

When  the  leaves  fall  in  autumn,  these  black  spore  cases 
fall  with  them,  and  the  spores  inside  remain  over  winter  to 
start  the  disease  anew  in  spring.  For  this  reason  they  are 
often  called  the  winter  spores. 

In  spring  or  early  summer  the  fungus  threads  get 
started  on  the  leaves.  Unlike  many  other  fungi,  the 
threads  do  not  grow  in  or  between  the  tissue  cells  of  the 
leaf,  but  they  remain  upon  the  outside  and  send  curious 
suckerlike  projections  in  through  the  breathing  pores  of 
the  leaf  to  absorb  food  from  the  cells. 

During  summer,  especially  before  the  development  of 
the  winter  spore  cases,  the  affected  leaves  often  have  a 
powdery  appearance.  This  is  due  to  the  development  of 
millions  of  tiny  white  spores.  Certain  threads  of  the  my- 
celium grow  out  at  right  angles  to  the  surface  of  the  leaf, 
and  on  their  ends  produce  spores  that  serve  for  the  spread 
of  the  fungus  during  the  warm  months.  These  are  called 
summer  spores  or  conidia. 


254  FARM   FRIENDS   AND   FARM   FOES 

A  great  many  different  kinds  of  powdery  mildews  are 
found  upon  wild  and  cultivated  plants.  One  of  the  most 
abundant  of  these  is  the  Cherry  Powdery  Mildew,  which 
occurs  also  on  apples  and  other  fruits.  It  is  especially  de- 
structive to  young  trees  in  nursery  rows.  The  Gooseberry 
Powdery  Mildew  is  another  widespread  and  destructive 
disease.  It  is  especially  likely  to  attack  English  varieties 
of  gooseberries  when  grown  in  America.  The  Grape 
Powdery  Mildew  is  also  more  or  less  injurious  over  most 
of  the  United  States,  and  the  Powdery  Mildew  of  the  Bean 
is  likewise  widely  injurious. 

The  powdery  mildews  live  externally  upon  the  leaves 
and  stalks  of  plants  more  than  is  the  case  with  most  para- 
sitic fungi.  Hence  we  would  expect  that  they  could  be 
easily  prevented  by  spraying  with  fungicides,  and  this  is 
true.  These  mildews  are  checked  by  applying  almost  any 
of  the  fungicides. 

OTHER  FUNGOUS  DISEASES 

A  considerable  number  of  fungous  diseases  are  due  to 
parasites,  the  complete  life  histories  of  which  have  not  yet 
been  discovered.  Such  fungi  are  commonly  classified 
under  the  heading  Fungi  Imperfecti  or  Imperfect  Fungi. 
The  imperfection,  however,  is  found  chiefly  in  our  lack  of 
knowledge.  As  the  diseases  are  more  carefully  investi- 
gated, the  parasites  are  being  transferred  to  the  various 
groups  to  which  they  belong. 

The  Potato  Scab  is  one  of  the  most  important  of  these 
diseases.  It  is  caused  by  an  inconspicuous  fungus  that  in 
freshly  dug  potatoes  may  often  be  seen  as  a  coating  of  fine 
white  threads  over  the  scabby  surface.  The  disease  occa- 
sionally occurs  upon  beets  and  other  root  crops.  Spores 
are  produced  among  these  threads.  It  is  now  well  estab- 


THE  ASCOSPORE   AND   OTHER   FUNGI 


255 


lished  that  on  potatoes  this  disease  may  be  prevented  by 
rotation  of  crops  and  soaking  the  tubers  to  be  planted  in  a 
solution  of  formalin  of  the  strength  of  one  ounce  to  two 
gallons  of  water. 

From  the  viewpoint  of  geographical  distribution,  the  Early 
Blight  of  the  Potato  seems  even 
more  important  than  the  Late 
Blight.  The  former  is  distrib- 
uted throughout  the  United 
States,  while  the  latter  is  chiefly 
destructive  in  New  York  and 
New  England.  The  Early 
Blight  appears  about  the  time 
the  plants  blossom,  showing  as 
small  brown  spots  scattered  over 
the  leaves.  Sometimes  the  spots 
enlarge  and  run  together  into 
blotches.  The  whole  plant  is 
often  killed  long  before  its  time, 
so  that  the  tubers  in  affected 
fields  are  small,  though  there  is 
no  rotting  effect  on  account 
of  this  disease.  Fortunately, 
spraying  with  Bordeaux  mixture  is  an  efficient  preventive. 

The  Anthracnose  of  Beans  is  another  widespread  and  im- 
portant disease.  It  is  familiar  to  most  people  who  have 
attempted  to  grow  string  beans,  because  the  reddish  brown 
spots  upon  the  pods  are  too  conspicuous  to  be  overlooked. 
Sometimes  the  disease  is  called  the  Pod  Spot.  Such  in- 
jured pods  are  generally  worthless,  and  the  whole  crop  is 
often  ruined  in  wet  seasons,  for  moisture  is  an  important 
factor  in  the  development  of  the  parasite. 

When   the  pods  are  seriously  affected  by  the  fungus, 


POTATO  LEAF  AFFECTED  BY 
EARLY  BLIGHT 


256  FARM   FRIENDS   AND   FARM   FOES 

the  beans  inside  are  also  liable  to  be  affected.  If  such 
beans  are  planted,  they  are  liable  to  start  the  disease  in  the 
new  crop.  Consequently,  the  selection  of  seed  from  fields 
or  pods  in  which  the  fungus  is  not  present  is  the  most 
promising  preventive  measure.  It  is  also  desirable  to  burn 
infested  vines  after  harvesting  as  well  as  to  rotate  the  crop 
and  select  for  it  high,  well-drained  land. 

The  Cotton  Anthracnose  is  an  important  disease  in 
many  Southern  states.  It  occurs  especially  upon  the  bolls, 
but  also  affects  other  parts  of  the  plant.  The  injury  to 
the  bolls  is  suggestive  of  that  upon  bean  pods,  and  the  af- 
fected bolls  are  likely  to  result  in  infected  seed. 

The  Anthracnose  of  Raspberry  and  Blackberry  is  an- 
other widespread  disease.  It  produces  characteristic  red- 
dish purple  spots  upon  the  young  canes  in  spring  and  sum- 
mer. The  centers  of  the  spots  later  become  grayish  white, 
and  the  spots  enlarge,  often  running  together  and  forming 
blotches.  The  spores  are  developed  in  dotlike  elevations. 

The  best  means  of  controlling  this  malady  are  found  in 
the  removal  of  affected  canes,  frequent  rotation  of  the 
plantation,  and  spraying  with  fungicides.  The  self-boiled 
lime-sulphur  wash  would  seem  worthy  of  trial  in  an  ex- 
perimental way. 

Still  another  Anthracnose  affects  green  grapes,  producing 
a  characteristic  injury  that  is  sometimes  called  Bird's-eye 
Rot.  It  occurs  upon  leaves  and  branches  as  well  as  the 
fruit,  but  is  most  destructive  to  the  latter.  The  destruc- 
tion of  diseased  portions  is  an  important  preventive  measure. 

CLUBROOT  OF  CABBAGE 

This  disease  is  caused  by  a  low  form  of  parasitic  fungus 
that  is  classed  with  the  group  of  Slime  Molds  rather  than 


THE  ASCOSPORE  AND   OTHER  FUNGI  257 

the  Imperfect  Fungi  where  the  diseases  discussed  in  the 
last  few  pages  are  classified.  The  fungus  causes  strange 
malformations  of  the  roots  of  cabbage,  cauliflower,  and 
other  wild  and  cultivated  members  of  the  mustard  family. 
It  reproduces  by  spores  and  is  especially  likely  to  develop 
in  acid  soils.  Consequently  liberal  applications  of  lime 
and  rotation  of  crops  are  helpful  methods  of  preventing  in- 
jury. Especial  care  should  be  taken  not  to  throw  diseased 
roots  upon  the  compost  heap.  It  is  better  to  burn  them. 

OBSERVATIONS   FOR   PUPILS 
BLACK  KNOT 

1.  Is   the   Black  Knot  abundant  in  your  locality  ?     Does  it  occur 
upon  wild  cherry  trees  ?     If  so,  upon  what  kind  of  wild  cherries  is  it 
most  abundant  —  the  choke  cherry,  the  wild  black  cherry,  or  the  wild 
red  cherry  ? 

2.  Notice  the  difference  between  the  dry  or  winter  condition  and 
the  velvety  or  summer  condition  of  the  knots.     Feel  the  velvety  coating. 

3.  If  a  microscope  is  available,  look  at  the  spores  from  the  velvety- 
surface  by  means  of  a  high  power. 

4.  What  preventive  measures  against  Black  Knot  are  used  in  your 
locality  ?     Is  there  a  law  in  your  state  requiring  property  owners  to 
destroy  the  knots  ? 

5.  Do  you  think  that  the  presence  of  this  disease  along  roads  and 
fences  and  in  dooryards  is  a  reflection  upon  the  efficiency  of  your  school 
as  an  agent  for  the  common  good  ?     If  so,  why  not  organize  a  campaign 
of  extermination  against  the  Black  Knot  ? 

6.  Has   one   man   a   right  to   allow  the   spores  of  Black  Knot  to 
develop  on  his  trees  to  be  blown  to  the  trees  of  his  neighbors  ? 

7.  Make  a  careful  sketch  of  a  twig,  showing  Black  Knot,  for  your 
booklet. 

POWDERY  MILDEWS 

1.  Look  at  leaves  of  lilac,  willow,  and  other  plants  to  find   those 
affected  by  the  whitish  covering  of  the  Powdery  Mildews. 

2.  Bring  such  leaves  to  school  and  study  them  as  directed  on  pages 


258  FARM   FRIENDS   AND   FARM   FOES 

253-254.     See  if  you  can  distinguish  the  summer  spores  and  the  winter 
spore  cases. 

3.  Make  a  list  of  the  Powdery  Mildew  diseases  that  you  know  to 
occur  in  your  locality. 

4.  Make  a  list  of  remedies  that  are  used  in  your  locality  to  prevent 
injury  by  these  diseases. 

5.  Make  sketches  of  the  fungi  as  seen  through  the  microscope,  also 
of  leaves  showing  spots  where  the  fungus  is  present. 

COTTON  DISEASES 

1.  Learn  what  diseases  are  most  destructive  to  cotton  in  your  region. 
Collect  specimens. 

2.  Read  such  of  these  references  as  your  teacher  directs  :  — 

Farmers'  Bulletins  302,  333. 

OTHER  DISEASES 

1 .  How  many  of  the  following  diseases  are  you  able  to  find  in  your 
locality  ?  — 

Peach  Leaf  Curl. 
Plum  Pockets. 
Strawberry  Leaf  Blight. 
Brown  Rot  of  Stone  Fruits. 
Black  Rot  of  Grapes. 
Bitter  Rot  of  Apples. 
Apple  Scab. 
Pear  Leaf  Blight. 

2.  Write  a  short  account  of  your  observations  upon  three  or  more  of 
these  diseases.     This  outline  may  help :  — 

The  abundance  of  the  disease. 

The  parts  of  the  host  affected  :  whether  leaf,  fruit,  or  bark. 

How  diseased  leaves  or  fruits  look. 

How  the  fungus  passes  the  winter. 

Preventive  measures. 

3.  Make  sketches  showing  the   characteristic  appearance   of  each 
disease  you  write  about. 


CHAPTER   XXIII 
Bacterial  Diseases  of  Plants 

THE  microscopic  one-celled  plants  called  Bacteria  or 
Microbes  are  now  known  to  be  the  cause  of  some  of  the 
most  destructive  plant  diseases.  In  a  way  the  life  history 
of  these  bacteria  is  simpler  than  that  of  many  of  the  fungi 
affecting  growing  crops.  The  bacteria  multiply  chiefly  by 
a  simple  division  of  the  cells,  each  single  cell  dividing  into 
two  cells.  This  is  a  very  rapid  process,  however,  so  that 
when  once  within  the  tissues  of  a  plant  the  disease-pro- 
ducing microbes  spread  very  quickly.  Consequently,  these 
diseases  are  often  called  Blights.  Another  appropriate 
name  for  some  of  them  is  Bacteriosis. 

PEAR  BLIGHT 

One  of  the  best-known  and  most  characteristic  of  these 
bacterial  diseases  is  the  Fire  Blight  of  the  Pear,  Quince, 
and  Apple.  The  leaves  on  the  branches  affected  by  this 
malady  suddenly  turn  black  as  if  injured  by  fire  and  hang 
upon  the  twigs  in  this  blighted  condition  for  some  time. 

This  Blight  affects  pear  trees  much  more  than  apple 
trees  and  is  the  most  serious  obstacle  in  the  way  of  suc- 
cessful pear  culture.  It  is  very  generally  known  simply 
as  the  Pear  Blight.  It  has  been  carefully  studied  by  many 
scientists,  so  that  the  characteristics  of  the  disease  are  well 
known.  The  microbe  causing  the  malady  was  named 
Bacillus  amylovorns  by  Professor  T.  J.  Burrill  of  Illinois. 

259 


260  FARM   FRIENDS   AND    FARM   FOES 

Drops  of  viscid  liquid  are  commonly  found  along  the 
margin  of  the  diseased  areas  of  the  bark.  These  are 
swarming  with  the  germs  of  the  Bacillus.  Bees  and  other 
insects  are  attracted  to  these  drops,  sucking  them  up  and 
getting  myriads  of  microbes  upon  their  feet  and  mouth 
parts. 

Many  bacteria  multiply  rapidly  in  sweet,  jelly  like  liquids. 
Such  a  liquid  is  found  in  the  nectar  cup  at  the  base  of  the 
pear  blossom,  and  to  a  less  extent  on  the  end  of  the  pistil 
of  the  same  flower.  Should  a  bee 
visit  a  diseased  tree  and  get  some 
of  the  blight  microbes  upon  its 
feet  or  mouth  parts,  and  then  visit 
the  blossoms  of  a  healthy  tree,  some 
of  these  germs  would  probably  be 
introduced  upon  the  nectar  of  the 
latter. 

CLAW  FROM  BEE'S  FOOT  When  thus  Placed  in  a  position 
WITH  BLIGHT  BACTERIA  favorable  to  growth,  the  bacteria 
TO  SHOW  THE  RELATIVE  multiply  rapidly,  and  follow  down 
SIZE  :  HIGHLY  MAGNIFIED  r  J  \ 

through  the  stalk  of  the  flower  to 

the  twig.  Here  they  continue  to  develop,  and  soon  may 
spread  downward  through  the  branch.  As  far  as  they  go 
they  kill  the  tissues,  causing  blossoms,  leaves,  and  twigs 
to  turn  black. 

The  germs  may  also  be  introduced  to  new  trees  through 
breaks  in  the  bark  or  by  the  gnawings  of  insects.  The 
disease  is  more  severe  in  trees  that  grow  rapidly  than  in 
those  that  grow  slowly.  Consequently  cultural  methods 
that  induce  rapid  growth  are  to  be  avoided.  The  prompt 
cutting  off  and  burning  of  all  affected  branches,  taking 
care  that  the  germs  are  not  distributed  by  saw,  knife,  or 
shears,  is  the  most  effectual  remedy. 


BACTERIAL   DISEASES   OF   PLANTS  261 

CROWN  GALL  DISEASE 

It  is  now  pretty  well  established  that  the  widespread 
disease  of  fruit  trees  called  Crown  Gall  is  caused  by  bac- 
teria. This  has  recently  become  one  of  the  most  destruc- 
tive maladies  of  trees,  having  been  widely  distributed 
through  nursery  stock  before  its  real  nature  was  discovered. 
This  disease  appears  in  spring  as  an  abnormal  growth  upon 
the  roots  of  apple,  pear,  peach,  and  other  trees,  as  well  as 
those  of  blackberries  and  raspberries  and  various  herba- 
ceous plants.  The  growth  continues  through  the  season, 
often  forming  large  galls  of  varied  shapes.  Ordinarily 
the  growth  ceases  at  the  end  of  the  first  season,  and  the 
gall  later  decays  and  disintegrates.  New  galls  are  likely 
to  appear  the  next  season  on  other  roots  in  large  num- 
bers, damaging  the  root  system  so  badly  that  the  tree  may 
finally  die. 

It  is  easy  to  see  how  readily  soil  could  be  inoculated  with 
crown-gall  germs.  If  a  diseased  tree  is  planted  and  later 
dug  up,  it  is  probable  that  millions  of  the  spores  will  remain 
in  the  ground.  Consequently  great  care  should  be  taken 
not  to  set  diseased  plants,  and  if  possible  to  get  plants  from 
nurseries  where  crown  gall  is  not  present. 

CABBAGE  ROT 

The  Cabbage  Rot  is  another  bacterial  disease  that  has 
been  carefully  studied  by  several  scientists  in  widely  sep- 
arated regions.  The  malady  is  especially  destructive  to 
cabbages,  often  ruining  large  fields.  It  also  attacks  cauli- 
flowers, turnips,  rutabagas,  and  various  other  plants  of  the 
mustard  family.  It  has  been  found  on  Charlock,  a  weed 
belonging  to  this  family,  and  probably  occurs  upon  other 
species. 


262  FARM   FRIENDS   AND   FARM   FOES 

The  fact  that  the  Cabbage  Rot  is  caused  by  a  bacterial 
germ  has  been  abundantly  demonstrated.  If  you  look 
at  cabbage  leaves  during  a  season  of  damp  weather,  you 
will  probably  see  a  row  of  water  drops  along  the  margin 
of  each  leaf.  These  have  come  out  from  small  pores, 
extending  from  the  margin  to  the  veins  of  the  leaf.  The 
leaves  are  constantly  giving  off  surplus  water  through 
the  pores ;  in  dry  weather  the  water  evaporates  as  it 
emerges,  but  in  moist  weather  it  remains  to  form  the  water 
drop. 

When  one  of  the  tiny  bacteria  carried  in  the  air  by  the 
wind  happens  to  lodge  in  one  of  these  water  drops,  it  begins 
to  multiply,  and  soon  develops  in  such  numbers  that  the 
bacteria  enter  the  leaf  through  the  water  pore.  Once  in- 
side, they  travel  down  the  veins,  causing  injury  as  they 
go,  until  they  reach  the  main  stalk.  They  follow  the  large 
channels  in  this  stalk,  and  sometimes  permeate  the  whole 
head  by  pushing  along  through  the  system  of  veins. 

The  injury  done  by  these  myriads  of  microbes  checks 
the  growth  of  the  plant  and  finally  kills  it.  The  germs  of 
other  microbes  soon  enter  the  injured  tissues  and  cause  a 
vile-smelling  rot  which  effectually  completes  the  work  of 
destruction. 

While  the  Cabbage  Rot  Bacterium  is  able  to  invade 
healthy  plants  through  the  pores,  it  is  often  introduced 
also  by  the  bites  of  insects.  If  an  insect  is  feeding  upon 
a  diseased  cabbage,  its  mouth  parts  are  likely  to  be  more 
or  less  covered  with  the  disease  germs.  If  it  then  bites  a 
healthy  plant,  some  of  these  germs  will  enter  the  tissues 
of  the  latter,  and  the  malady  be  started  anew. 

The  disease  has  proved  very  difficult  to  overcome. 
Crop  rotation  and  clean  culture  are  helpful,  but  they  are 
by  no  means  always  effective.  The  selection  of  healthy 


BACTERIAL   DISEASES   OF   PLANTS  263 

plants  from  the  seed  bed  is  important.  Warm,  moist 
weather  is  favorable  to  the  development  of  the  malady. 
Duggar  advises  soaking  the  seed  for  twenty  minutes  in 
formalin  solution,  one  part  to  two  hundred  parts  water. 

OTHER  BACTERIAL  DISEASES 

The  Bacteriosis  or  Blight  of  the  Bean  and  related  plants 
is  another  destructive  disease.  It  affects  especially  the 
pods,  producing  soft  spots  with  a  characteristic  water- 
soaked  appearance.  More  rarely  it  attacks  the  stems  and 
leaves.  Apparently  the  disease  may  be  started  through 
infected  seeds,  so  that  care  to  select  seeds  from  blight-free 
fields  is  desirable. 

The  Bacteriosis  of  melons,  cucumbers,  and  other  vines 
is  still  another  destructive  malady.  The  bacteria  develop 
in  enormous  numbers  in  the  water  channels  of  the  plants, 
thus  preventing  water  from  reaching  the  leaves,  and  caus- 
ing the  sudden  wilting  of  the  latter.  Flea  beetles,  striped 
beetles,  and  other  insects  help  to  carry  the  microbes  from 
plant  to  plant. 

Corn  and  celery  are  both  subject  to  bacterial  diseases, 
and  cotton  bolls  are  attacked  by  microbes  that  cause  the 
Cotton  Boll  Rot.  Potatoes,  tomatoes,  and  eggplants  are 
the  victims  of  another  bacterium  that  causes  injury  to 
leaves  and  tubers  or  fruits. 

OBSERVATIONS   FOR   PUPILS 
PEAR  BLIGHT 

1.  Have  you  ever  seen  pear  trees  injured  by  this  disease? 

2.  How  did  it  show  itself  ? 

3.  Have  you  seen  blighted  apple  branches? 

4.  Read  this  reference :  — 

Pear  Blight :  Its  Cause  and  Prevention,  Yearbook  Reprint  500. 


CHAPTER   XXIV 
Preventives  of  Fungous  Diseases 

IN  a  general  way  the  methods  used  to  prevent  injury  by 
fungous  diseases  come  under  the  head  of  preventives  rather 
than  of  remedies.  Even  in  cases  where  an  injured  part  of 
a  plant  is  cut  off,  the  aim  is  to  prevent  further  spread  of  the 
disease  within  the  tissues  of  the  plant  or  to  the  tissues  of 
other  plants.  When  the  fungus  has  once  invaded  the  cells, 
there  is  little  hope  of  remedy  so  far  as  the  affected  part 
of  the  host  is  concerned.  In  the  case  of  the  external 
mycelium  of  the  powdery  mildews,  however,  the  fungicide 
may  have  a  direct  effect. 

The  various  fungicides  are  really  preventives  rather  than 
remedies.  They  kill  the  spores  or  mycelium  threads  upon 
the  outer  parts  of  the  plants  treated,  or  they  lie  in  wait  to 
kill  whatever  spores  may  come  to  seek  entrance  to  the  tis- 
sues. The  chemicals  of  the  fungicides  do  not  enter  the  tis- 
sues of  the  host  to  destroy  the  fungus  threads  among  the  cells. 

It  is  evident  that  the  prevention  of  the  ravages  of  fun- 
gous diseases  is  a  broad  subject.  Many  ways  will  readily 
occur  to  one  who  thinks  of  the  myriads  of  parasitic  fungi 
and  their  varied  host  plants.  These  ways  may  all  be 
grouped,  however,  under  two  general  topics  :  namely,  ( i ) 
the  destruction  of  the  parasite ;  (2)  the  prevention  of  its 
growth  upon  or  within  the  host. 

PREVENTIVE  MEASURES 

Taking  up  the  latter  topic  first,  we  find  that  for  many 
fungous  diseases  the  most  important  method  of  prevention 

264 


PREVENTIVES  OF  FUNGOUS  DISEASES          265 

lies  in  the  selection  of  varieties  or  strains  of  varieties  that 
are  able^o  resist  the  attacks  of  the  parasite.  In  the  case 
of  the  grain  rusts  as  well  as  of  many  other  diseases,  this 
seems  to  be  the  only  practical  way  of  preventing  injury. 
It  is  of  the  greatest  importance  that  disease-resisting  sorts 
be  planted  of  all  crops  in  which  there  is  a  variation  in  this 
ability.  Crop  growers  should  always  be  on  the  alert  to  dis- 
cover individual  plants  that  are  able  to  resist  the  parasites. 
One  may  thus  develop  a  strain  of  greatest  value. 

Some  years  ago  an  asparagus  field  in  one  of  the  central 
Western  states  was  struck  by  the  asparagus  rust.  In  the 
great  area  of  reddened  plants,  only  one  stood  out  green  and 
flourishing.  Through  some  peculiarity  of  its  life  substance 
it  was  able  to  resist  the  attacks  of  the  fungus.  The  owner 
had  the  good  sense  to  see  that  this  plant  might  be  made 
the  parent  of  a  resisting  race.  So  he  saved  the  seed, 
selected  the  most  resistant  plants  that  grew  from  them,  and 
in  a  few  years  was  able  to  introduce  to  the  trade  a  valuable 
variety. 

Similar  progress  has  been  made  in  the  selection  of  vari- 
eties of  cotton  able  to  withstand  the  dreaded  wilt  disease 
for  which  no  remedy  is  known. 

The  selection  of  disease-resistant  plants  and  the  breeding 
of  new  varieties  from  them  is  now  occupying  the  attention 
of  many  painstaking  men.  Much  progress  has  already 
been  made,  and  we  may  soon  expect  great  benefit  from  their 
labors. 

Another  important  method  of  preventing  the  growth  of  the 
parasite  upon  its  host  is  so  to  isolate  the  crop  that  the  fun- 
gus may  not  reach  it.  In  the  case  of  many  diseases,  the 
spores  of  which  are  carried  far  and  wide  through  the  air, 
this  is  not  practicable.  Many  of  the  rusts,  for  example, 
travel  great  distances  on  the  wind,  and  thus  reach  crops 


266  FARM   FRIENDS   AND   FARM   FOES 

on  new  ground.  In  the  case  of  many  other  diseases,  how- 
ever, the  fungus  remains  in  the  soil  from  year  to  year,  and 
unless  crop  rotation  is  practiced,  each  succeeding  season 
is  likely  to  show  greater  damage.  This  is  notably  true  of 
some  of  the  smut  diseases:  a  garden  in  which  sweet  corn 
was  grown  for  many  years  finally  produced  few  ears  that 
were  not  injured.  This  fact  makes  more  plain  the  lesson 
of  all  good  agriculture  that  a  rotation  of  crops  is  one  of 
the  first  essentials  to  success. 

In  general,  good  tillage  and  fertilization  help  to  prevent 
injury  by  fungous  diseases.  Many  plants  seem  better  able 
to  grow  without  damage  by  fungi  when  they  are  in  a 
vigorous  condition.  This  is  not  always  true,  however,  for 
the  very  rapidity  of  growth  in  some  plants  produces  condi- 
tions favorable  to  the  development  of  the  parasite.  Pear 
trees  of  quick  growth  are  much  more  liable  to  blight  thaji 
those  of  slower  growth,  and  grains  growing  vigorously  seem 
to  be  more  liable  to  injury  by  rusts  than  those  of  slower 
growth. 

Sometimes  it  is  possible  to  exclude  the  germs  of  the  para- 
sites by  mechanical  means.  The  various  mildews  and  rots 
that  affect  grapes  are  readily  excluded  by  fastening  paper 
bags  over  the  stems  soon  after  the  fruit  is  set. 

In  many  instances  the  easiest  way  to  prevent  the  spores 
of  fungi  from  reaching  new  hosts  is  through  the  direct  de- 
struction of  the  fungus  that  produces  the  spores.  This  is 
obviously  a  practical  method  that  may  be  adopted  under 
greatly  varying  conditions.  In  general  it  involves  clean 
culture  and  the  destruction  of  refuse  materials  upon  which 
spores  may  be  developed.  The  plants  of  many  crops  may 
continue  to  produce  fungus  spores  after  the  fruits  are 
gathered,  and  the  burning  or  deep  burying  of  such  plants 
is  very  desirable.  In  the  case  of  species  of  fungi  that 


PREVENTIVES  OF  FUNGOUS  DISEASES          267 

alternate  from  one  host  to  another  the  destruction  of  one 
form  may  prevent  the  development  of  the  other.  Thus, 
the  easiest  way  to  prevent  injury  by  apple  rust  is  to  cut 
down  the  cedar  trees  on  which  the  infecting  spores  develop. 
In  the  case  of  others,  the  fungus  may  develop  on  wild 
plants  and  the  spores  be  carried  to  those  cultivated.  Thus, 
in  fighting  black  knot  in  plum  and  cherry  orchards  it  is 
essential  that  the  infested  wild  cherry  trees  in  the  same 
locality  be  destroyed. 

REMEDIAL  MEASURES 

The  use  of  fungicides  —  or  substances  that  kill  fungi  — 
has  recently  become  the  most  generally  adopted  method  of 
preventing  these  diseases.  These  substances  are  applied 
to  the  surface  of  the  soil,  stems,  foliage,  or  fruit,  where  they 
may  kill  the'  spores  present  at  the  time  and  may  also  re- 
main for  a  considerable  period  in  condition  to  destroy  any 
spores  that  subsequently  alight. 

The  various  salts  of  copper  are  among  the  most  impor- 
tant fungicides.  These  are  used  in  a  great  many  ways,  but 
the  most  important  combination  is  that  of  copper  sulphate, 
commonly  called  blue  vitriol  with  lime  and  water.  This 
mixture  was  first  used  in  Bordeaux,  France,  to  prevent  cer- 
tain grape  diseases.  So  it  is  generally  called  the  Bordeaux 
mixture.  It  is  now  the  most  widely  used  fungicide  and  is 
recognized  as  a  sure  preventive  of  many  plant  maladies. 
The  usual  formula  is  :  Copper  sulphate,  4  pounds ;  unslaked 
lime,  4  pounds ;  water,  50  gallons. 

The  application  of  Bordeaux  mixture  to  apple  trees  often 
causes  a  troublesome  russeting  of  the  fruit  that  lessens  the 
value  of  the  crop.  On  this  account,  dilute  lime-sulphur 
washes  are  used  in  its  place  in  many  orchards. 

Copper  sulphate  is  also  used  in  simple  water  solution. 


268  FARM   FRIENDS   AND   FARM   FOES 

For  spraying  dormant  trees  in  winter  or  early  spring,  it  is 
used  at  the  rate  of  one  pound  dissolved  in  fifty  gallons  of 
water.  For  spraying  trees  in  leaf  it  is  used  at  the  rate  of 
two  ounces  dissolved  in  fifty  gallons  of  water. 

Carbonate  of  copper  is  also  used  as  a  fungicide.  It  is 
generally  prepared  as  follows :  Three  ounces  of  the  car- 
bonate are  to  be  dissolved  in  three  pints  of  ammonia,  the 
whole  then  being  added  to  a  barrel  of  water.  The  pow- 
dered carbonate  dissolves  more  readily  if  it  is  first  made 
into  a  paste  by  mixing  with  water.  One  advantage  of  this 
fungicide,  which  is  used  for  the  prevention  of  apple  scab 
and  various  mildews,  is  that,  being  a  clear  solution,  there  is 
no  clogging  of  nozzles,  as  sometimes  happens  with  the  Bor- 
deaux mixture. 

Sulphide  of  potassium  or  liver  of  sulphur  is  sometimes 
used  to  prevent  the  mildew  on  the  leaves  and  fruit  of  goose- 
berries. Half  an  ounce  is  dissolved  in  two  gallons  of  hot 
water,  and  the  solution  when  cold  is  applied  to  bushes  in 
the  form  of  a  spray. 

Powdered  sulphur,  commonly  called  flowers  of  sulphur, 
is  valuable  as  a  fungicide  for  some  forms  of  fungi  affecting 
plants.  It  is  used  in  California  as  a  preventive  of  asparagus 
rust.  The  fumes  that  rise  from  the  sulphur  on  the  hot  soil 
in  sunshine  kill  the  rust  spores. 

The  lime-sulphur  spray  used  as  a  remedy  for  scale  in- 
sects is  also  a  fungicide.  It  has  proved  one  of  the  best 
remedies  for  peach-leaf  curl,  brown  rot  of  stone  fruits,  apple 
scab,  and  other  diseases. 

Solutions  of  formalin  have  been  found  of  great  value  as 
fungicides  in  the  treatment  of  potato  scab  and  grain  smuts. 
Fortunately,  this  substance  is  now  taking  the  place  of  cor- 
rosive sublimate  —  a  poison  too  dangerous  to  use  unless 
absolutely  necessary. 


PREVENTIVES  OF  FUNGOUS  DISEASES          269 

COMBINING  INSECTICIDES  AND  FUNGICIDES 

In  many  cases  it  has  been  found  that  a  fungicide  is  also 
of  value  as  an  insecticide,  and  vice  versa.  In  others,  it  is 
easy  to  add  an  insecticide  to  the  fungicide  solution,  and  thus 
prevent  both  classes  of  injury  by  one  application.  A  Bor- 
deaux mixture  with  arsenate  of  lead  added  is  the  combina- 
tion most  frequently  used  in  the  past,  but  it  seems  likely  to 
be  displaced  by  the  combination  arsenate  of  lead  and  the 
lime-sulphur  wash. 

"  The  successful  orchardist  of  the  future,"  writes  W.  M. 
Scott,  "  will  be  the  man  who,  among  other  things,  studies 
the  conditions  existing  on  his  own  farm  and  sprays  his 
trees  according  to  the  needs  of  each  variety  for  the  control 
of  the  particular  troubles  which  occur  in  his  locality. 
The  course  of  treatment  best  suited  for  the  orchards 
of  the  Shenandoah  Valley  of  Virginia  may  not  neces- 
sarily give  the  best  results  in  orchards  situated  east  of 
the  Blue  Ridge  in  that  state,  and  again  the  treatment  for 
certain  varieties  of  apples  may  be  different  from  that  re- 
quired for  certain  other  varieties  growing  in  the  same 
locality.  The  course  of  treatment  should  be  planned  not 
only  with  reference  to  the  diseases  to  be  controlled,  but 
also  with  reference  to  the  probable  effect  of  the  fungicide 
upon  the  fruit  and  foliage  of  the  variety  to  be  treated. 
The  Ben  Davis,  for  example,  is  so  seriously  russeted  by 
applications  of  Bordeaux  mixture  that  often  most  of  the 
fruit  sprayed  with  this  fungicide  is  rendered  second  class. 
In  Virginia  this  variety  does  not  suffer  materially  from  the 
attacks  of  scab,  bitter  rot,  or  other  serious  fruit  diseases,  the 
leaf  spot  which  is  easily  controlled  being  its  chief  fungous 
enemy.  The  Ben  Davis  in  Virginia  and  in  other  similar 
situations  may  therefore  be  successfully  sprayed  with  a 


270  FARM  FRIENDS  AND   FARM   FOES 

weak  fungicide  which  will  control  the  leaf  spot,  sooty  fungus, 
and  slight  scab  infections  without  injury  to  the  fruit  or  foli- 
age. The  York  Imperial  is  another  variety  which  has  no 
serious  disease  of  the  fruit,  and  in  addition  it  is  not  subject 
to  Bordeaux  russet,  so  common  on  the  Ben  Davis,  but  the 
foliage  is  susceptible  to  leaf  spot  and  is  often  badly  injured 
by  applications  of  Bordeaux  mixture. 

"  On  the  other  hand,  the  Yellow  Newtown  is  seriously 
subject  to  the  attacks  of  bitter  rot  and  must  be  treated  with 
a  strong  fungicide,  such  as  Bordeaux  mixture,  for  the  con- 
trol of  this  disease.  The  fruit  of  this  variety  is  susceptible 
to  Bordeaux  injury,  but  since  such  injury  is  produced  only 
by  the  early  applications  of  the  mixture,  the  treatment  may 
be  so  planned  as  to  avoid  it.  One  of  the  lime-sulphur 
sprays  may  be  used  for  the  first  and  second  sprayings  after 
the  petals  fall,  and  Bordeaux  mixture  for  the  bitter  rot 
treatments  which  come  later.  These  are  the  finer  points 
to  be  considered  in  connection  with  spraying,  and  the 
orchardist  who  gives  them  due  consideration  will  obtain 
the  best  results  in  the  production  of  good  fruit." 

The  National  Department  of  Agriculture  issues  bulletins 
giving  precise  directions  for  the  preparation  of  fungicides. 
These  are  frequently  revised,  and  should  be  obtained  when 
fungicides  are  to  be  prepared. 

OBSERVATIONS   FOR   PUPILS 

1 .  What  methods  of  preventing  plant  diseases  are  employed  in  your 
neighborhood  ? 

2.  Do  the  more  progressive  farmers  use  the  spraying  machine  or  those 
less  progressive  ? 

3.  Read  such  of  these  references  as  your  teacher  may  request :  — 
Spraying  for  Cucumber  and  Melon  Diseases,  Farmers'  Bulletin  231.     Fungicides 

and  their  Use  in  preventing  Diseases  of  Fruits,  Farmers'  Bulletin  243.  Insect  and 
Fungous  Enemies  of  the  Grape  east  of  the  Rocky  Mountains,  Farmers'  Bulletin 
284.  Grape  Diseases  on  the  Pacific  Coast,  Farmers'  Bulletin  30. 


CHAPTER   XXV 
Fungous  Diseases  of  Insects 

DID  you  ever  notice  on  the  window  pane  in  autumn  a 
dead,  swollen  fly  sticking  to  the  glass  by  its  tongue  and 
feet,  with  a  circle  of  white,  powdery  dots  about  it  resem- 
bling a  halo,  and  with  an  abdomen  so  swollen  that  it 
seems  to  be  made  up  of  alternating  black  and  white  rings  ? 
If  you  break  the  fly  apart,  you  will  probably  find  it  brittle, 
and  with  a  lens  you  can  see  whitish  threads  inside. 

This  fly  is  the  victim  of  a  parasitic  fungus  somewhat 
similar  to  many  of  the  fungi  that  cause  disease  and  death 
in  the  higher  plants.  The  white  dots  are  the  spores  of 
the  fungus  thrown  out  from  the  fruiting  threads  that  have 
developed  in  the  body.  By  means  of  these  spores  other 
living  flies  may  catch  the  disease  and  die. 

One  who  understands  how  dangerous  flies  are  as  carriers 
of  the  germs  of  typhoid  fever  and  other  diseases  of  man- 
kind will  not  regret  that  they  themselves  are  thus  destroyed 
by  this  parasitic  fungus.  Consequently  it  is  easy  to  ac- 
knowledge that  we  have  friends  as  well  as  foes  in  the  great 
group  of  fungi. 

The  halo-producing  fly  parasite  is  a  typical  example  of 
the  family  of  Insect-killing  Fungi  (Entomophthoreae).  It 
belongs  to  the  genus  Empusa,  so  called  because  the  Greeks 
in  ancient  times  used  the  name  Empusa  when  they  fancied 
they  saw  "a  weird  specter  of  constantly  changing  shape." 

A  parasitic  fungus  closely  related  to  that  which  attacks 
the  house  fly  often  occurs  in  colonies  of  aphides  or  plant 

271 


272  FARM  FRIENDS   AND   FARM   FOES 

lice.  During  moist  weather,  which  is  especially  favorable 
to  the  growth  of  fungous  diseases  of  insects,  this  aphid 
parasite  often  destroys  billions  of  victims,  checking  destruc- 
tive outbreaks  of  crop  pests.  You  can  readily  distinguish 
with  a  lens  the  plant  lice  that  are  killed  by  the  fungus  from 
those  killed  by  insect  parasites. 

A  similar  fungus  is  often  very  helpful  in  checking  out- 
breaks of  the  chinch  bug,  and  has  been  the  subject  of 
many  investigations  to  determine  whether  it  can  be  utilized 
as  a  remedy  for  this  insect.  Dead  bugs  covered  with  the 
whitish,  moldlike  growth  of  the  fungus  may  generally 
be  found  wherever  chinch  bugs  are  abundant.  While 
probably  the  artificial  propagation  and  dissemination  of 
the  bugs  hastens  the  spread  of  the  malady,  the  success  of 
the  measure  is  largely  dependent  upon  the  damp  weather 
favorable  to  the  development  of  the  disease. 

Fortunately  these  insect-killing  fungi  attack,  caterpillars 
of  many  kinds.  A  short  search  among  cabbages  will  often 
show  a  cabbage  worm  killed  by  such  a  disease.  The  body 
of  the  caterpillar  is  filled  with  the  fungous  threads  which 
convert  it  into  a  mummified  condition,  and  finally  produce 
upon  the  surface  a  crop  of  spores.  Many  other  insects,  es- 
pecially grasshoppers,  are  attacked  by  a  similar  disease. 

CATERPILLAR  FUNGI  (Ascomycetes) 

Another  group  of  these  insect  parasites  attacks  caterpil- 
lars of  many  kinds,  and  are  often  called  the  Caterpillar 
Fungi.  They  belong  to  the  great  group  of  Ascospore 
Fungi  to  which  so  many  diseases  of  plants  belong.  They 
are  readily  distinguished  by  the  strange,  clublike  projection 
in  which  the  ascospores  are  developed.  Two  of  these 
mushroom-like  bodies  coming  from  a  fly  are  shown  in  the 
picture  on  the  next  page.  White  grubs  are  often  killed 


FUNGOUS  DISEASES  OF  INSECTS  273 

by  a  fungus  belonging  to  this  group,  developing  a  curious 
growth  that  generally  projects  from  the  head. 

WHITE  FLY  FUNGI 

One  of  the  most  noted  illustrations  of  the  effect  of  para- 
sitic fungi  upon  injurious  insects  is  found  in  the  case  of 
the  White  Fly  or  Aleyrodes,  various  species  of  which  are 
destructive  to  orange  and  other  trees  in  the  Southern  and 
Pacific  coast  states.  Similar  species  are  also 
destructive  in  greenhouses  in  the  North. 
At  least  seven  distinct  forms  of  the  fungi  are 
known  to  attack  these  insects,  and  many 
successful  experiments  have  been  made  in 
spreading  the  diseases  artificially.  The  most 
effective  way  is  by  washing  into  water  the 
spores  that  have  developed  on  the  insects  killed  by  dis- 
ease, and  spraying  the  water  on  the  infested  plants.  The 
Florida  Experiment  Station  has  shown  that  this  method  is 
easy  and  effective.  The  spraying  apparatus  must  have  no 
copper  in  it,  except  the  nozzle,  as  faint  traces  of  copper  are 
liable  to  kill  the  spores.  Another  method  is  simply  to  pin 
leaves  covered  with  the  dead  insects  upon  the  branches  of 
trees  that  are  infested  by  White  Flies.  The  disease- 
producing  fungi  are  most  likely  to  spread  during  wet 
weather. 

BACTERIAL  DISEASES 

The  diseases  of  insects  due  to  Bacteria  are  perhaps 
more  important  than  any  others.  When  tent  caterpillars, 
cutworms,  army  worms,  or  various  other  insects  become  ex- 
tremely abundant,  they  often  die  suddenly  in  great  num- 
bers, seeming  to  be  affected  by  a  sort  of  cholera  that  causes 
death  and  rapid  decay.  This  is  a  bacterial  disease. 


274  FARM   FRIENDS   AND   FARM  FOES 

Not  all  bacterial  diseases  of  insects,  however,  are 
helpful  to  man.  The  Foul  Brood,  which  is  so  destructive 
to  honey-bees,  and  the  dreaded  flacherie  of  silkworms,  are 
both  due  to  these  microscopic  germs.  They  cause  great 
losses  to  the  bee-raising  and  silk  industries. 

OBSERVATIONS   FOR   PUPILS 

1.  In  autumn  look  for  flies  that  show  the  ring  of  spores  around  them. 

2.  Look  for  diseased  aphides  or  plant  lice,  especially  between  cab- 
bage leaves  and  on  clover  plants. 

3.  Keep  watch    for    dead  grasshoppers    clinging   to   the    tops  of 
wire  fences  or  herbaceous  plants. 

4.  If  you  live  in  a  region  where  chinch  bugs  are  found,  hunt  for 
dead,  moldy  specimens. 

5.  If  you  live  in  a  region  where  white   flies  are  abundant,  look 
for  those  killed  by  fungus,  and  try  spreading  the  disease. 

6.  When  you  find  any  of  these  diseased  insects,  place  them  in  a 
glass,  add  a  few  drops  of  water,  and  cover  tightly.     Watch  daily  for  the 
development  of  spores.     Examine  these  under  the  microscope. 

7.  Read  this  reference :  —  Nature  Biographies,  pages  89-95. 


BACTERIA;  HIGHLY  MAGNIFIED 


CHAPTER   XXVI 
Bacteria  and  Plant  Food 

IT  has  been  shown  in  an  earlier  chapter  that  the  micro- 
scopic forms  of  life  called  microbes  or  bacteria  often  cause 
serious  losses  on  account  of  the  blights  and  rots  that  they 
induce  in  plants.  Such  bacteria  are  true  parasites,  develop- 
ing within  the  tissues  of  living  plants  and  causing  injury 
and  death.  It  is  well  known  that  vast  numbers  of  bacteria 
are  similarly  parasitic  upon  animal  life,  causing  many  of 
the  most  fatal  diseases  in  man  and  the  lower  animals. 
Most  of  these  forms  of  germ  life  must,  of  course,  be 
reckoned  among  the  farmer's  foes. 

THE  NITRIFYING  BACTERIA 

There  are  many  other  bacteria,  however,  that  may  well 
claim  to  be  friendly  to  the  farmer,  for  they  serve  an  im- 
portant purpose  in  furnishing  food  to  his  crops.  One 
group  of  these  is  present  in  vast  numbers  in  fertile  soils 
where  they  help  to  form  the  nitrates  which  are  very  im- 
portant in  supplying  food  to  plants.  The  plant  or  animal 
materials  added  to  the  soil  for  fertilizing  purposes  con- 
tain nitrogen  in  combination  with  various  other  elements. 
Consequently  most  of  the  nitrogen  in  the  soil  exists  in  the 
form  of  these  organic  compounds  —  that  is,  compounds 
made  by  organized  or  living  things.  In  order  that  the 
nitrogen  in  these  organic  compounds  may  be  utilized  by 
growing  plants,  it  must  be  recombined  to  form  nitrates  — 

275 


276  FARM  FRIENDS  AND   FARM   FOES 

that  is,  combinations  of  nitrogen,  oxygen,  and  some  element 
like  lime  or  potash  —  which  are  readily  absorbed  through 
the  roots  of  plants. 

There  are  certain  sorts  of  bacteria  the  special  function 
of  which  is  to  convert  the  organic  nitrogen  into  nitrates. 
These  are  called  the  Nitrifying  Bacteria.  During  this 
process  the  organic  material  is  first  converted  into  an  am- 
monia form,  then  into  a  nitrite  form,  and.  finally  into  the 
nitrate  form.  In  a  general  way  this  is  a  change  from  a 
condition  in  which  the  nitrogen  is  insoluble  into  a  condition 
in  which  it  is  readily  dissolved. 

During  recent  years  the  importance  of  this  nitrifying 
process  has  received  a  great  deal  of  attention.  It  is  now 
recognized  that  good  farming  involves  such  treatment  of 
the  soil  that  these  friendly  germs  may  do  as  much  work  as 
possible,  and  that  their  abundance  is  an  important  test  of 
soil  fertility. 

THE  NITROGEN-GATHERING  BACTERIA 

In  addition  to  the  store  of  nitrogen  in  the  soil  which  is 
unavailable  until  it  is  changed  into  the  nitrate  form  by  the 
nitrifying  bacteria,  there  is  an  even  greater  store  of  it  in 
the  air.  This  supply  is  so  great  that  it  has  been  estimated 
that  there  are  seventy-five  million  pounds  of  nitrogen  rest- 
ing upon  every  acre  of  land.  This  nitrogen  in  the  air, 
however,  cannot  be  used  directly  by  plants,  so  that  it 
seems  to  have  little  value  as  a  fertilizer. 

But  here  again  the  friendly  germs  come  to  the  farmer's 
help.  If  you  dig  up  a  vigorous  red  clover  plant  and  wash 
the  soil  carefully  away  from  its  roots,  you  will  probably  find 
upon  the  latter  many  small,  roundish  tubercles.  If  you  treat 
a  soy  bean  plant  in  the  same  way,  you  will  find  a  condition 
like  that  pictured  on  the  opposite  page.  And  you  may  easily 


BACTERIA  AND   PLANT  FOOD 


277 


find  similar  tubercles  upon  the  roots  of  beans,  peas,  vetches, 
sweet  clover,  alfalfa,  and  various  other  members  of  the  great 
family  of  legumes,  or  pod  bearers. 

It  took  a  long  while  for  man  to  trace  the  connection 
between  these  tubercles  upon  the  roots  of  the  pod-bearing 
plants  and  the  free  nitrogen  of  the  air.  There  is  still  much 
mystery  about  it,  but  we  now  know  that  the  tubercles  or 
nodules  are  composed  chiefly  of 
colonies  of  bacteria,  and  that  these 
bacteria  are  able  to  convert  the 
free  nitrogen  in  the  air  between 
the  soil  particles  into  a  form  that 
is  utilized  by  the  plants.  They 
may  well  be  called  the  Nitrogen- 
gathering  Bacteria,  and  are  to  be 
classed  among  the  farmer's  best 
friends. 

We  have  seen  that  some  bac- 
teria may  live  as  parasites  upon 
living  plants  or  animals:  these  are 
the  Parasitic  Bacteria.  We  have 
also  seen  that  some  bacteria  — 
including  the  nitrifying  forms  — 
may  live  as  saprophytes  upon  dead 
and  decaying  plants  or  animals:  these  are  the  Saprophytic 
Bacteria.  We  have  now  to  determine  the  relation  of  the 
nitrogen-gathering  bacteria  to  the  leguminous  plants.  Evi- 
dently they  are  not  parasites,  for  they  help  rather  than  in- 
jure the  growth  of  the  plant.  Nor  are  they  saprophytes, 
for  they  develop  upon  living  rather  than  dead  plants.  They 
seem  to  form  a  sort  of  partnership  with  the  plants.  They 
need  a  home  to  grow  in  and  some  help  to  get  their  growth  ; 
in  return  they  gather  nitrogen  for  the  benefit  of  their  hosts. 


ROOT  OF  SOY  BEAN  SHOW- 
ING TL'BF.RCLES 


278  FARM   FRIENDS   AND    FARM   FOES 

When  we  speak  of  two  plants  thus  living  together  in  mutual 
helpfulness,  we  use  the  word  symbiosis :  so  we  say  that  the 
nitrogen-gathering  germs  are  Symbiotic  Bacteria. 

These  symbiotic  bacteria  are  of  great  importance  to  prac- 
tical agriculture.  In  most  good  systems  of  crop  rotation, 
clover  or  some  other  leguminous  plant  is  grown  every  few 
years  in  order  that  the  supply  of  available  nitrogen  in  the 
soil  may  be  increased.  Clover  is  able  to  increase  this  supply 
because  of  the  help  given  by  the  germs  living  in  the  nod- 
ules on  the  clover  roots.  One  of  the  best  ways  to  improve 
poor  soil  is  to  grow  a  leguminous  crop  and  plow  it  under 
as  green  manure.  The  value  of  this  process  lies  largely 
in  the  presence  of  the  nitrogen-gathering  bacteria.  When 
an  alfalfa  field  is  well  established,  it  may  be  left  undisturbed 
except  for  harvesting  the  crops,  for  many  years.  Presum- 
ably it  is  able  thus  to  yield  its  forage  year  after  year  be- 
cause the  bacteria  in  the  nodules  on  the  roots  are  gathering 
free  nitrogen  from  the  air. 

A  striking  example  of  the  effectiveness  of  these  bacteria 
in  gathering  nitrogen  has  been  recorded  by  the  Illinois  Ex- 
periment .Station.  Three  sets  of  ten  cowpea  plants  with 
tubercles  on  the  roots  were  analyzed  to  determine  the  per- 
centage of  nitrogen.  Three  other  sets  of  ten  cowpea  plants 
without  tubercles  were  also  analyzed  for  comparison.  "  The 
infected  plants  contained  nearly  four  times  as  much  nitrogen 
as  the  plants  not  infected,  and  about  three  fourths  of  the 
total  nitrogen  in  the  infected  plants  was  obtained  from  the 
air.  The  roots  and  tubercles  of  the  infected  plants  con- 
tained six  to  seven  times  as  much  nitrogen  as  the  roots  of 
the  plants  not  infected." 

It  is  an  interesting  fact  that  the  bacteria  found  in  nodules 
on  the  roots  of  red  clover  will  not  develop  upon  the  roots 
of  cowpeas  or  several  other  related  plants.  Similarly,  the 


BACTERIA   AND    PLANT   FOOD 


279 


bacteria  from  cowpeas  will  not  develop  upon  red  clover. 
Thus  in  a  broad  way  we  may  say  that  each  distinct  legumi- 


NO  NITROGEN 
BACTERIA 


NO  NITROGEN 

BACTFR'A 


RED  CLOVER  :  EFFECT  OF  BACTERIA 

nous  crop  has  a  special  form  of  symbiotic  microbe  and  that, 
as  a  rule,  these  microbes  are  not  interchangeable. 

DECAY  OF  NODULES 

Another  important  fact  is  that  most  of  these  bacteria 
are  unable  to  live  independently  in  the  soil  more  than  five 
or  six  years  after  the  crop  on  which  they  develop  has 
disappeared.  Consequently  we  cannot  expect  to  find  in  a 
given  soil  the  various  germs  waiting  to  develop  upon  any 
leguminous  crop  that  may  be  planted.  Nor  in  most  cases 
is  it  safe  to  assume  that  enough  of  these  germs  will  adhere 


280  FARM   FRIENDS  AND   FARM   FOES 

to  the  seed  and  be  planted  with  them  to  insure  a  good  de- 
velopment of  tubercles  upon  the  roots. 

Consequently,  the  conditions  that  exist  in  a  given  case 
may  be  something  like  this :  Here  is  a  field  in  which  no 
red  clover  has  been  grown  in  a  dozen  years.  The  soil  is 
poor  and  sour.  It  produces  very  small  crops  and  evi- 
dently needs  to  be  improved.  We  wish  to  grow  red  clover 
to  help  its  condition.  Evidently  we  must  get  rid  of  the 
sourness  by  a  liberal  application  of  lime  or  some  other 
alkaline  fertilizer.  Then  we  must  introduce  the  clover 
tubercle  germs  into  the  soil  and  sow  the  seed.  Such  intro- 
duction of  germs  is  often  spoken  of  as  inoculation  —  that 
is,  we  inoculate  the  soil  with  the  desired  microbes  in  the 
expectation  that  when  introduced  they  will  thrive  and 
multiply  upon  the  clover  roots.  One  of  the  simplest  ways 
of  inoculating  is  to  bring  a  quantity  of  soil  from  a  field  in 
which  clover  has  been  growing  successfully.  Being  sure 
that  the  plants  grown  in  the  soil  have  shown  plenty  of 
nodules,  spread  it  broadcast  and  harrow  it  in.  We  may 
thus  get  a  very  general  dispersal  of  the  germs  where  they 
will  come  in  contact  with  the  developing  clover  roots. 

Another  way  to  inoculate  the  soil  is  to  shake  up  in  a 
bottle  of  water  a  small  quantity  of  soil  from  a  thriving 
clover  field.  Let  it  stand  until  the  soil  particles  settle,  and 
pour  the  clear  liquid  over  the  clover  seed  or  upon  the  soil 
where  the  seed  is  planted.  This  method  is  especially  use- 
ful in  pot  experiments. 

Fortunately,  these  nitrogen-gathering  bacteria  can  be 
induced  to  develop  in  vast  numbers  in  what  are  called 
nutrient  solutions.  The  scientists  of  the  United  States 
Department  of  Agriculture  have  been  at  work  for  many 
years  upon  the  methods  of  growing  bacteria  in  such  solu- 
tions. They  have  succeeded  so  well  that  the  Department 


BACTERIA   AND   PLANT   FOOD  281 

now  offers  to  the  public  small  culture  tubes  of  the  microbes 
of  each  of  the  important  leguminous  crops,  with  precise 
directions  for  their  use.  This  enables  any  one  to  inoculate 
his  soil  for  any  crop  desired. 

Experience  has  shown  that  with  some  crops  at  least  it  is 
worth  while  at  first  to  grow  the  same  crop  for  two  suc- 
cessive seasons  in  order  to  secure  a  thorough  inoculation  of 
the  soil.  After  that,  if  the  crop  is  grown  in  rotation  every 
four  or  five  years,  the  microbes  are  likely  to  continue 
present  in  such  numbers  that  further  inoculation  is  un- 
necessary. 

The  germs  that  grow  upon  cowpeas  seem  very  generally 
present  in  the  soil  of  the  Southern  states.  Consequently 
it  is  seldom  necessary  to  inoculate  for  this  crop. 

The  germs  that  grow  upon  sweet  clover  or  melilot  seem 
to  be  able  to  develop  with  equal  vigor  upon  alfalfa.  Con- 
sequently, it  is  often  practicable  to  inoculate  alfalfa  fields 
with  soil  in  which  sweet  clover  has  been  growing. 

OBSERVATIONS   FOR   PUPILS 

1.  Make  a  list  of  the  leguminous  plants  in  your  locality  upon  which 
you  find  root  tubercles. 

2.  Compare  the  abundance  of  the  tubercles  with  the  vigor  of  the 
plant. 

3.  Grow  red  clover  in  sand  or  other  soil  deficient  in  nitrogen,  being 
sure  it  is  from  a  field  where  red  clover  has  not  grown.      Apply  the 
germs  obtained  as  suggested  on  page  280,  to  part  of  the  pots,  but  not  to 
all.     See  which  set  grows  best,  making  sketches  every  two  weeks. 

4.  Read  such  of  these  references  as  your  teacher  directs  :  — 

Leguminous  Crops  for  Green  Manuring,  Farmers'  Bulletin  278.  Progress  in 
Legume  Inoculation,  Farmers'  Bulletin  315.  The  Renovation  of  Worn-out  Soils, 
Farmers'  Bulletin  245.  Alfalfa,  Farmers'  Bulletin  339.  Clover  Farming  on  the 
Sandy  Jack-pine  Lands  of  the  North,  Farmers'  Bulletin  323.  Canadian  Field 
Peas,  Farmers'  Bulletin  224.  Cowpeas,  Farmers'  Bulletin  318.  The  Liming  of 
Soils,  Farmers'  Bulletin  77. 


PART   IV 

• 

FRIENDS   AND    FOES    AMONG   THE 
BIRDS 


A  PAGE  FROM  A  BIRD  BOOKLET 


THE  BOOKLET  ON  BIRDS 

Birds  are  more  difficult  to  draw  than  plants  or  insects.  Consequently 
this  booklet  is  likely  to  have  fewer  pages  of  drawings  of  the  birds  themselves, 
though  these  may  readily  be  replaced  by  drawings  of  fruits,  seeds,  and  insects 
which  are  eaten  by  birds,  as  well  as  by  mounted  pictures  cut  from  magazines. 

Abundant  opportunities  for  written  or  printed  pages  may  be  found  in  the 
suggestions  at  the  ends  of  the  chapters  on  birds.  Delightful  poems  con- 
cerning birds  are  readily  found  and  may  be  copied  for  the  booklet. 


CHAPTER  XXVII 
The  Relations  of  Birds  to  Fruit  Orchards 

IN  a  large  part  of  North  America  the  apple  is  the  lead- 
ing orchard  fruit.  The  pear  and  the  peach  are  much  less 
generally  grown,  although  each  is  important  in  certain 
localities.  The  same  is  true  of  cherries,  plums,  and  quinces, 
though  in  the  aggregate  each  of  these  fruits  is  of  great 
value. 

These  orchard  trees  are  subject  to  attack  by  a  great  variety 
of  insect  enemies.  Root,  trunk,  branch,  twig,  leaf,  and 
fruit  —  each  part  has  special  enemies  that  too  often  blight 
the  crop.  Fortunately,  however,  most  of  these  enemies  are 
largely  held  in  check  by  various  birds  that  frequent  the 
orchards  and  help  to  keep  a  balance  that  is  favorable  to 
fruit  production.  Where  birds  are  scarce  the  task  of  fruit- 
raising  is  greatly  increased. 

TRUNK,  ROOTS,  AND  BRANCHES 

The  trunk  and  the  larger  roots  and  branches  of  most 
fruit  trees  are  subject  to  attack  by  a  great  variety  of  burrow- 
ing insects.  In  general,  the  eggs  are  laid  on  or  in  the  bark 
by  a  winged  beetle  or  moth.  These  eggs  hatch  into  larvae 
that  burrow  in  bark,  sapwood,  or  heartwood,  remaining  at 
work  until  full  grown  as  larvae.  They  then  change  to  pupae, 
generally  in  or  near  the  outer  bark,  and  emerge  later  as 
adult  beetles  or  moths. 

Common  examples  of  such  destructive  insects  are  found 
in  the  round-headed  apple-tree  borer,  the  flat-headed  borer, 

285 


286  FARM   FRIENDS   AND   FARM   FOES 

the  peach-tree  borer,  the  fruit-bark  beetle,  and  the  sinuate 
pear  borer. 

Set  over  against  these  enemies  of  trunk  and  branch,  we 
find  the  woodpeckers,  nuthatches,  creepers,  and  chickadees. 
These  birds  are  constantly  searching  the  bark  for  the  larvae 
and  pupae  concealed  within,  and  they  are  wonderfully  adapted 
both  to  discover  the  position  of  the  pests  and  to  dig  them 
out.  The  long,  barbed  tongue  of  the  woodpecker  can  be 
thrust  into  the  hole  made  by  a  borer  and  draw  the  larva 
quickly  forth.  The  larger  and  more  deeply  embedded 
larvae  are  especially  sought  by  the  woodpeckers,  while  the 
smaller  insects  on  or  near  the  surface  are  eaten  by  the 
nuthatches,  creepers,  and  chickadees. 

The  twigs  or  smaller  branches  of  fruit  trees  are  attacked 
by  a  great  variety  of  insect  enemies.  The  sap  is  sucked 
through  the  bark  by  hosts  of  scale  insects  or  bark  lice,  and 
aphides  or  plant  lice,  as  well  as  by  tree  hoppers  and  related 
pests.  Many  of  the  birds  already  mentioned  feed  freely 
upon  these  various  insects,  the  nuthatches,  creepers,  and 
chickadees  being  especially  useful  in  this  respect.  These 
are  not  alone,  however,  in  the  good  work.  They  are 
assisted  by  the  orioles,  sparrows,  vireos,*  warblers,  gros- 
beaks, wrens,  gnat  catchers,  bluebirds,  and  other  feathered 
friends.  In  the  case  of  the  scale  insects  alone,  fifty-seven 
kinds  of  birds  have  been  listed  as  feeding  on  them. 

BUDS  AND  LEAVES 

When  we  consider  the  relations  of  birds  to  the  enemies 
of  the  buds  and  leaves  of  orchard  trees,  we  find  so  close  a 
connection  that  we  are  forced  to  conclude  that  the  life  of 
the  trees  depends  upon  the  birds.  Tree  leaves  are  beset  by 
a  bewildering  host  of  insect  enemies.  Aphides,  scale  in- 


RELATIONS  OF   BIRDS  TO  ORCHARDS 


287 


sects,  leaf  hoppers,  and  many  other  true  bugs  suck  out  the 
sap ;  leaf  miners  of  many  sorts  mine  the  leaves ;  while 
beetles,  grasshoppers,  crickets,  and  numberless  caterpillars 
devour  the  blades. 

Set  over  against  these  myriads  of  leaf-feeding  insects, 
we  find  the  great  majority  of  our  familiar  birds.  Watch 
the  birds  in  an  orchard  on  a  summer  day  and  you  will  be 
convinced  of  their  great  value 
as  insect  destroyers.  If  you 
are  keen-eyed  and  patient, 
you  will  see  the  warblers  and 
other  smaller  birds  searching 
leaf  after  leaf  for  aphides  and 
tiny  caterpillars,  while  vireos, 
bluebirds,  robins,  thrushes, 
sparrows,  cedar  birds,  cuckoos, 
catbirds,  blackbirds,  and  others 
are  devouring  the  larger  en- 
emies. If  you  watch  these 
birds  at  their  nests,  you  will 
see  that  the  young  are  fed 
with  vast  numbers  of  such 
insect  foes.  Even  in  winter 
the  eggs  and  pupae  are  con- 
tinually eaten  by  birds. 

The  enemies  of  the  fruits  of  orchard  trees  are  less 
numerous  than  those  of  the  leaves,  but  still  their  name  is 
legion.  Scale  insects,  beetles,  bugs,  caterpillars,  maggots, 
midges,  and  other  pests  all  attack  one  kind  of  fruit  or 
another,  often  destroying  the  bulk  of  the  crop.  The  birds 
that  attack  these  enemies  are  nearly  as  numerous  as  those 
that  attack  leaf -feeding  insects,  and  the  good  they  do  is 
incalculable. 


TENT-CATERPILLAR  NEST  AT- 
TACKED BY  BIRDS 


288  FARM   FRIENDS   AND   FARM    FOES 

What  is  true  of  the  relations  between  insects  and  birds 
in  orchards  of  deciduous  fruits  is  equally  true  in  orchards 
of  citrous  fruits.  Wherever  oranges,  lemons,  and  related 
trees  are  grown  for  profit,  hosts  of  insect  enemies  attack  the 
trees.  These  insects  are  preyed  upon  by  birds  which  help 
greatly  in  checking  the  injuries  of  the  pests. 

AERIAL  INSECTS 

Nearly  all  the  insects  that  affect  orchards  exist  part  of 
their  lives  in  a  winged  condition  in  which  they  fly  through 
the  air  from  branch  to  branch  or  from  tree  to  tree.  At 
such  times  they  are  in  danger  of  being  snapped  up  by 
flycatchers,  vireos,  swallows,  and  other  birds.  Most  of 
these  keep  watch  over  comparatively  limited  spaces  near 
the  trees,  but  the  whole  realm  of  the  air  is  patrolled 
by  the  swallows.  Over  the  water  or  above  the  land  the 
flying  insect  is  in  danger  of  being  suddenly  captured  in  the 
swallow's  beak.  The  food  of  swallows  consists  chiefly  of 
insects  thus  caught  upon  the  wing ;  beetles,  flies,  ants,  and 
small  moths  are  all  taken  in  great  numbers.  Consequently, 
these  birds  are  as  useful  as  they  are  beautiful,  and  should 
be  encouraged  by  every  one. 

At  night,  also,  the  war  against  flying  insects  is  kept  up 
by  the  whippoorwills  and  nighthawks.  These  interesting 
birds  patrol  the  air  in  dusk  and  darkness,  catching  flying 
insects  of  many  kinds  in  their  capacious  jaws. 

OTHER  ENEMIES 

There  are  other  enemies  of  orchard  trees  besides  the  in- 
sects. The  trunks  are  frequently  girdled  by  meadow  mice 
and  rabbits  that  gnaw  the  bark.  This  generally  happens 
in  winter,  when  the  mice  work  beneath  the  surface  of  the 


RELATIONS   OF   BIRDS   TO   ORCHARDS  289 

snow.  Fortunately,  however,  hawks,  owls,  and  other  large 
birds  feed  freely  upon  these  pests  and  commonly  keep 
their  numbers  so  reduced  that  little  damage  is  done.  But 
in  regions  where  the  hawks  and  owls  are  ruthlessly  perse- 
cuted, the  mice  and  other  rodents  become  destructive,  and 
often  cause  the  loss  of  valuable  trees. 

It  would  perhaps  be  too  much  to  expect  that  birds 
should  do  no  harm  in  orchards  to  offset  the  immense  good 
they  do.  In  certain  ways  they  doubtless  cause  damage, 
but  this  is  on  the  whole  vastly  less  than  the  benefit  they 
confer.  Some  birds  eat  fruit,  especially  cherries,  to  a 
serious  extent.  It  is  indeed  probably  true  that  in  fruit- 
growing regions  there  are  often  more  robins  than  are 
beneficial  to  horticulture. 

Birds  also  cause  the  spread  of  scale  insects  and  probably 
of  fungous  diseases,  although  little  real  injury  is  done  in 
these  ways.  At  least  one  bird — the  true  sapsucker  — 
sometimes  injures  the  trees  by  boring  holes  in  the  bark 
and  taking  the  sap,  though  this  should  not  lead  to  the 
killing  of  the  beneficial  woodpeckers,  which  the  sapsucker 
resembles. 

The  chief  damage  done  to  fruit  by  birds  generally 
results  from  the  extraordinary  abundance  of  one  kind  of 
bird.  Thus,  in  the  eastern  region  of  the  United  States  the 
robin  is  often  troublesome  because  it  occurs  in  great  num- 
bers and  attacks  cherries  and  small  fruits.  On  the  Pacific 
coast  it  is  sometimes  very  destructive  in  olive  orchards. 
In  the  latter  region  birds  are  more  injurious  to  fruit  than 
in  the  East,  partly  because  of  the  scarcity  of  wild  fruits. 
The  house-finch  or  linnet,  the  Brewer  blackbird,  the  black- 
headed  grosbeak,  and  the  California  jay  often  become 
serious  pests,  although  each  of  these  doubtless  does  con- 
siderable good  in  other  ways. 


290  FARM   FRIENDS   AND   FARM   FOES 


OBSERVATIONS   FOR   PUPILS 
BIRDS  IN  APPLE  ORCHARDS 


1 .  Make  a  list  of  the  birds  you  have  seen  searching  the  bark  of  the 
trunk  and  larger  branches  of  apple  trees. 

2.  What  birds  occur  on  apple  trees  in  winter? 

3.  What  birds  have  the  habit  of  snapping  up  insects  in  the  air? 

4.  Make  a  list  of  all  the  different  birds  that  you  can  find  in  apple 
orchards. 

B 

1.  Write  a  little  story  with  this  title  :  The  Birds  in  Our  Orchard. 
Simply  tell  what  you  have  seen. 

2.  Read  as  many  of  these  references  as  you  have  access  to :  — 

Birds  in  their  Relation  to  Man,  pages  1-8,  68-80,  304-315.  Useful  Birds  and 
their  Protection,  pages  149-154.  How  Birds  Affect  the  Orchard,  Yearbook  Reprint 
197.  Does  it  Pay  the  Farmer  to  Protect  the  Birds  ?  Yearbook  Reprint  443.  The 
Relations  between  Birds  and  Insects,  Yearbook  Reprint  486. 


CHAPTER    XXVIII 
The  Relations  of  Birds  to  Meadows  and  Pastures 

WHILE  the  insects  that  affect  the  grasses  of  meadow 
and  pasture  lands  are  by  no  means  so  numerous  as  in  the 
case  of  the  orchards,  there  are  enough  to  prove  seriously 
destructive  at  times.  If  this  is  true  with  the  constant 
check  the  birds  keep  upon  them,  there  is  little  doubt  that 
they  would  do  vastly  greater  damage  were  there  no  birds. 

The  various  forms  of  locusts  or  grasshoppers  with  short 
antennae  are  among  the  most  abundant  of  meadow  and 
pasture  pests.  They  are  nearly  always  present  in  sufficient 
numbers  to  do  some  damage,  and  often  become  so  abundant 
as  to  destroy  the  growing  crop.  The  meadow  grasshoppers 
with  long  antennae,  are  often  abundant  enough  to  do  some 
injury.  The  much  smaller  leaf  hoppers  are  also  nearly  al- 
ways present  and  do  much  more  damage  than  is  generally 
supposed.  Many  sorts  of  cutworms,  including  the  notorious 
army  worm,  are  always  feeding  on  the  blades  of  grass  near 
the  ground,  and  other  kinds  of  caterpillars 
are  continually  at  work. 

In  addition  to  these  enemies  of  the  stems 
and  blades,  the  roots  of  grasses  are  attacked 
by  many  pests.  The  voracious  white  grubs 
—  the  larvae  of  the  familiar  May  beetles;  the 

slender  yellow  wireworms  —  the  larvae  of  the 

MAY  BEETLE 
common  click  beetles;    the  curious  meadow 

maggots — the  larvae  of  the  long-legged  crane  flies, — these 
and  many  other  pests  feed  upon  the  roots  of  grasses. 

291 


292  FARM  FRIENDS   AND   FARM   FOES 

The  clovers  and  other  forage  crops  often  grown  in  mead- 
ows have  their  special  insect  enemies  that  furnish  food  for 
many  birds. 

The  variety  of  bird  life  that  is  found  in  grasslands  is 
also  much  smaller  than  in  the  case  of  orchards.  Compar- 
atively few  species  have  adapted  themselves  to  live  upon 
the  ground  in  grasses,  but  these  few 
are  of  immense  benefit  as  destroyers 
of  insect  pests. 

The    most    notable    meadow   and 
pasture  birds  are  these :  the  meadow 
lark,    the    crow,    the  various   black- 
CLICK  BEETLES  birds,    the    bobolink,    the    cowbirds, 

the  ground  sparrows,  and  the  robin. 

While  these  do  not  all  live  exclusively  on  the  ground  in 
grasslands,  they  find  there  an  important  part  of  their  yearly 
food  supply. 

The  Meadow  Lark  is  a  typical  example  of  these  birds.  It 
is  an  abundant  and  widely  distributed  species,  living  habit- 
ually in  grasslands  and  finding  there  practically  all  its  food. 
Originally  a  native  of  the  great  prairie  regions,  it  has  grad- 
ually spread  as  forests  have  been  replaced  by  fields  and 
meadows  until  it  is  now  found  over  practically  the  whole 
of  the  United  States. 

The  food  of  the  Meadow  Lark  has  been  carefully  studied 
by  many  competent  investigators.  In  Illinois  Professor 
Forbes  found  that  at  least  three  quarters  of  the  food  during 
the  spring  and  summer  consisted  of  insects.  Cutworms, 
army  worms,  and  other  caterpillars  formed  more  than  a 
quarter  of  the  food  supply,  while  various  beetles  formed  a 
fifth  and  grasshoppers  more  than  an  eighth.  The  beetles 
eaten  included  June  beetles,  blister  beetles,  curculios, 
click  beetles,  and  plant  beetles.  Twenty  chinch  bugs 


RELATIONS   OF   BIRDS   TO   MEADOWS  293 

had  been  eaten  by  one  bird,  and  others  had  devoured 
crane  flies. 

Studies  in  other  places  show  similar  results  and  bring 
out  the  fact  that  in  autumn  when  insects  become  more 
scarce  the  Meadow  Lark  feeds  freely  upon  the  seeds  of 
weedy  plants.  It  consequently  is  of  great  value  wherever 
it  is  found,  and  should  be  given  the  most  careful  protection. 

The  Bobolink  is  one  of  the  most  delightful  of  meadow 
birds.  It  is  also  one  of  the  most  useful,  for  it  feeds  freely 
on  grasshoppers,  caterpillars,  and 
other  insect  pests  as  well  as  on  the 
seeds  of  weedy  plants.  In  the 
North  it  is  eminently  beneficial, 
though  on  its  way  southward  it 
often  becomes  a  pest  in  rice  fields. 

While  it  cannot  fairly  be  claimed        MEADOW  GRASSHOPPER 
that    the    Crow    and    the   various 

Blackbirds  are  entirely  beneficial,  there  is  no  doubt  that 
they  do  much  good  to  offset  some  harm.  So  far  as  their 
actions  concern  meadows  and  pastures,  these  birds  are  of 
benefit,  for  they  devour  vast  numbers  of  grasshoppers, 
cutworms,  army  worms,  white  grubs,  June  beetles,  and 
other  pests.  The  harm  they  do  is  chiefly  in  grain  fields, 
either  at  the  time  of  planting  or  that  of  harvesting. 

There  are  several  kinds  of  Sparrows  that  live  more  or 
less  on  the  ground  in  pastures  and  meadows.  The  more 
important  are  these  :  the  Field  Sparrow,  Song  Sparrow, 
Vesper  Sparrow,  Savanna  Sparrow,  and  the  Dickcissel. 
All  of  these  birds  feed  freely  upon  grass  insects,  destroying 
vast  numbers  of  crickets,  grasshoppers,  cutworms,  and  other 
caterpillars,  as  well  as  the  seeds  of  weedy  -plants.  The 
young  are  also  fed  with  similar  insects,  so  that  these  birds 
are  eminently  beneficial. 


294 


FARM   FRIENDS   AND   FARM   FOES 


The  presence  of  flocks  of  Robins  searching  grasslands 
for  food  is  one  of  the  characteristic  sights  of  early  spring. 
At  no  other  season,  perhaps,  do  these  birds  search  so 
persistently  upon  the  ground.  A  large  proportion  of  the 
grasshoppers,  cutworms,  army  worms,  and  other  grass 
insects  that  have  succeeded  in  living  through  the  winter 

are  then  eaten  by  the 
Robins.  This  early 
spring  destruction  of 
such  pests  is  of  great 
value  in  checking  their 
increase,  and  the  birds 
atone  for  many  sins  in 
the  cherry  trees  by 
their  actions  at  this 
season. 

No  consideration  of 
the  relations  of  birds 
to  insects  of  grass- 
lands would  be  ade- 
quate that  did  not 
take  account  of  the 
flycatchers,  swallows, 

swifts,  whippoorwills,  and  nighthawks,  a  large  part  of 
whose  food  consists  of  grasshoppers,  leaf  hoppers,  beetles, 
moths,  and  other  pests  of  grasslands. 

As  their  name  indicates,  the  meadow  mice  are  often  very 
destructive  in  pastures  and  meadows.  They  destroy  much 
grass  by  feeding  upon  crowns  or  roots,  and  their  runways 
in  spring  often  show  how  busy  they  have  been  beneath 
the  snow  in  winter.  The  hawks  and  owls  are  the  most 
important  natural  checks  upon  these  pests.  The  experi- 
ences of  many  regions  show  that  where  these  birds  are 


SCREECH  OWL 


RELATIONS   OF   BIRDS   TO   MEADOWS  295 

relentlessly  persecuted,  the  meadow  mice  are  likely  soon 
to  multiply  to  an  alarming  extent,  sometimes  destroying  the 
crops  in  whole  fields. 

OBSERVATIONS   FOR   PUPILS 
BIRDS  IN  MEADOWS  AND  PASTURES 

1.  Make  a  list  of  the  most  important  grass-feeding  insects  in  your 
locality. 

2.  Make  a  list  of  the  birds  you  have  seen  upon  the  ground  in  pas- 
tures or  meadows,  or  both. 

3.  Make  a  list  of  the  birds  that  build  their  nests  on  the  ground  in 
pastures  and  meadows. 

4.  Read  as  many  of  the  following  references  as  are  accessible  :  — 

Farmers'  Bulletin  54,  pages  15-28.  The  Bird  Book,  pages  248-253.  Birds  in 
their  Relations  to  Man,  pages  137-144,  158-171.  Useful  Birds  and  their  Protection, 
pages  76-80,  310-333. 


CHAPTEB    XXIX 
The  Relations  of  Birds  to  Gardens  and  Fields 

THE  conditions  in  regard  to  the  crops  and  insects  of 
gardens  and  cultivated  fields  vary  in  different  regions. 
Consequently,  it  seems  best  to  indicate  the  relations  of 
birds  to  them  by  considering  a  few  of  the  more  widely 
distributed  species  that  live  chiefly  in  such  situations. 

SPARROWS 

The  little  Chipping  Sparrow  is  one  of  the  most  abun- 
dant of  the  smaller  birds  found  in  gardens  and  fields  near 
houses.  In  the  North  it  arrives  early  in  spring  and  remains 
till  late  in  autumn.  Its  food  consists  of  insects  and  the 
seeds  of  grasses  and  weeds.  Nearly  half  of  the  food  often 
consists  of  the  seeds  of  such  noxious  plants  as  pigeon 
grass  and  crab  grass.  Cutworms,  cankerworms,  bugs, 
moths,  ants,  beetles,  and  grasshoppers  are  among  the 
insects  eaten  by  both  young  and  adults.  In  consequence 
of  such  feeding  habits,  this  familiar  little  bird  is  very  use- 
ful and  should  be  encouraged  in  every  way  possible. 

On  account  of  its  attractive  voice  the  Song  Sparrow  is 
perhaps  an  even  greater  favorite  than  the  Chipping  Spar- 
row. It  is  found  everywhere  in  fields  and  gardens,  keep- 
ing close  to  the  ground  where  insects  and  weed  seeds  are 
abundant.  It  remains  through  the  winter  as  far  north  as 
Massachusetts. 

The  other  native  ground-loving  sparrows  —  such  as  the 
Field  Sparrow,  the  Savanna  Sparrow,  the  Vesper  Sparrow, 

296 


RELATIONS   OF  BIRDS   TO   GARDENS  297 

and  the  Junco  —  have  similar  feeding  habits.  They  are 
especially  useful  as  destroyers  of  the  seeds  of  weeds.  In 
this  respect,  however,  they  are  probably  surpassed  by  the 
related  sparrows  that  do  not  live  so  much  upon  the  ground. 
These  include  the  Tree  Sparrow,  the  Goldfinch,  the  White- 
crowned  Sparrow,  the  White-throated  Sparrow,  and  the 
Snowflake.  These  are  preeminently  seed  eaters,  and  they 
undoubtedly  destroy  thousands  of  tons  of  weed  seeds  every 
year. 

The  bird  commonly  known  as  the  English  Sparrow 
was  brought  into  America  from  Europe  in  1850  and  again 
three  years  later.  These  birds  were  imported  because  it 
was  thought  that  they  would  assist  in  the  suppression  of 
the  cankerworm,  an  insect  very  destructive  to  the  leaves 
of  shade  trees.  After  their  introduction  they  thrived  and 
spread  rapidly,  being  carried  by  man  from  city  to  city  so 
that  before  many  years  they  were  very  generally  distrib- 
uted. 

English  sparrows  are  by  preference  city  birds;  they  utilize 
all  sorts  of  crevices  about  buildings  for  nesting  and  roost- 
ing purposes,  and  live  upon  a  great  variety  of  food.  From 
towns  they  gradually  disperse  through  the  surrounding 
country,  congregating  about  farm  buildings.  They  breed 
rapidly,  and  have  few  enemies.  When  well  fed,  they  can 
stand  very  cold  weather  without  injury. 

As  a  destroyer  of  noxious  insects,  this  sparrow  has  been 
generally,  though  not  always,  a  failure.  There  are  also 
many  misdemeanors  charged  to  him.  It  is  known  that  he 
habitually  destroys  the  buds  and  blossoms  of  trees,  and  at- 
tacks ripening  fruit  of  many  kinds,  as  well  as  peas  on  the 
vines  and  seeds  in  the  soil.  Grains  in  the  field  are  also 
devoured  by  the  sparrows  ;  houses  are  made  filthy  by  their 
presence ;  and  native  birds  are  driven  away  by  them. 


298  FARM   FRIENDS  AND   FARM   FOES 

With  these  and  other  charges  the  sparrows  stand  indicted ; 
and  they  have  comparatively  little  good  to  counterbalance 
the  evil.  Consequently,  it  would  seem  that  they  should 
not  be  encouraged  near  farm  buildings. 

BLUEBIRDS,  ROBINS,  AND  CATBIRDS 

Next  to  the  sparrow,  the  Bluebird  is  one  of  the  most 
abundant  species  found  in  gardens  and  cultivated  fields. 
Fortunately,  this  universal  favorite  is  as  useful  as  it  is  beau- 
tiful. Its  food  has  been  most  carefully  studied  by  Profes- 
sor S.  A.  Forbes,  who  writes  :  "  One  hundred  bluebirds  at 
thirty  insects  each  a  day  would  eat  in  eight  months  about 
730,000  insects.  If  this  number  of  birds  were  destroyed, 
the  result  would  be  the  preservation  on  the  area  supervised 
by  them  of  about  70,000  moths  and  caterpillars  (many  of 
them  cutworms),  12,000  leaf  hoppers,  10,000  curculios,  and 
65,000  crickets,  locusts,  and  grasshoppers.  How  this 
frightful  horde  of  marauders  would  busy  itself  if  left  un- 
molested no  one  can  doubt.  It  would  eat  grass  and  clover 
and  corn  and  cabbage,  inflicting  an  immense  injury  itself 
and  leaving  a  progeny  that  would  multiply  that  injury 
indefinitely." 

The  Robin  is  very  useful  in  destroying  insects  that  live 
on  or  in  the  ground.  It  feeds  freely  upon  such  pests  as 
cutworms,  white  grubs,  and  grasshoppers.  It  is  especially 
busy  in  meadows  when  it  first  arrives  in  early  spring. 

The  food  of  the  Robin  as  determined  by  the  investiga- 
tions of  the  United  States  Department  of  Agriculture  has 
been  summarized  as  follows :  "  An  examination  of  300 
stomachs  shows  that  over  42  per  cent  of  its  food  is  animal 
matter,  principally  insects,  while  the  remainder  is  made 
up  largely  of  small  fruits  or  berries.  Over  19  per  cent 


RELATIONS   OF   BIRDS   TO    GARDENS  299 

consists  of  beetles,  about  one  third  of  which  are  useful 
ground  beetles,  taken  mostly  in  spring  and  fall  when  other 
insects  are  scarce.  Grasshoppers  make  up  about  one 
tenth  of  the  whole  food,  but  in  August  comprise  over  30 
per  cent.  Caterpillars  form  about  6  per  cent,  while  the 
rest  of  the  animal  food,  about  7  per  cent,  is  made  up  of 
various  insects,  with  a  few  spiders,  snails,  and  angle 
worms.  All  the  grasshoppers,  caterpillars,  and  bugs,  with 
a  large  part  of  the  beetles,  are  injurious,  and  it  is  safe  to 
say  that  noxious  insects  comprise  more  than  one  third  of 
the  robin's  food.  Vegetable  food  forms  nearly  58  per  cent 
of  the  stomach  contents,  over  47  being  wild  fruits,  and  only 
a  little  more  than  4  per  cent  being  possibly  cultivated  va- 
rieties. Cultivated  fruit  amounting  to  about  25  per  cent 
was  found  in  the  stomachs  in  June  and  July,  but  only  a 
trifle  in  August.  Wild  fruit,  on  the  contrary,  is  eaten  in 
every  month,  and  constitutes  a  staple  food  during  half  the 
year.  No  less  than  41  species  were  identified  in  the 
stomachs ;  of  these,  the  most  important  were  four  species 
of  dogwood,  three  of  wild  cherries,  three  of  wild  grapes, 
four  of  greenbrier,  two  of  holly,  two  of  elder ;  and  cran- 
berries, huckleberries,  blueberries,  barberries,  service  ber- 
ries, hackberries,  and  persimmons,  with  four  species  of 
sumac,  and  various  seeds  not  strictly  fruit." 

There  is  no  doubt  that  the  Robin  is  a  very  useful  bird, 
when  we  consider  its  life  through  the  year.  But  it  is  also 
true  that  at  times,  especially  in  fruit-growing  regions,  it  is 
decidedly  injurious. 

No  country  boy  needs  to  be  introduced  to  the  Catbird. 
It  is  familiar  to  every  one  who  has  wandered  along  a 
roadside  or  by  the  margin  of  woods.  It  is  a  useful  bird, 
although  it  sometimes  helps  itself  too  freely  to  the  fruits 
of  the  orchard  and  garden.  "Ants,  beetles,  caterpillars, 


300  FARM   FRIENDS   AND   FARM   FOES 

and  grasshoppers  constitute  three  fourths  of  the  animal 
food,"  writes  Professor  Beal,  "  the  remainder  being  made 
up  of  bugs,  miscellaneous  insects,  and  spiders.  One 
third  of  the  vegetable  food  consists  of  cultivated  fruits 
or  those  which  may  be  cultivated,  such  as  strawberries, 
raspberries,  and  blackberries ;  but  while  we  debit  the  bird 
with  the  whole  of  this,  it  is  probable  —  and  in  the  eastern 
and  well-wooded  part  of  the  country  almost  certain  —  that 
a  large  part  was  obtained  from  wild  vines.  The  rest  of 
the  vegetable  matter  is  mostly  wild  fruit,  such  as  cherries, 
greenbrier,  spice  berries,  black  alder,  sumac,  and  poison 
ivy."  About  half  of  the  food  of  the  Catbird  is  of  animal 
and  half  of  vegetable  nature.  Planting  wild  fruits  in  out- 
of-the-way  corners  is  recommended  to  keep  these  birds 
away  from  the  fruit  garden. 

BLACKBIRDS  AND  CROWS 

Two  kinds  of  Blackbirds  are  generally  to  be  found  in  the 
Northern  states.  The  larger  of  these  is  the  Crow  Black- 
bird, of  which  there  are  two  forms  —  the  Bronzed  Crackle  and 
the  Purple  Crackle,  large  and  handsome  birds,  familiar  to 
country  boys  throughout  their  range.  Their  food  consists 
of  insects,  grains,  and  other  vegetable  matter,  insects 
forming  about  one  third  of  the  total.  These  birds  are 
frequently  destructive  to  ripening  wheat  or  other  grain 
crops,  and  no  doubt  often  do  as  much  harm  as  good.  But 
in  general  they  should  not  be  molested  except  when 
causing  damage. 

The  Redwinged  Blackbird  is  smaller  than  the  Crackles, 
although  in  regions  favorable  for  its  breeding  it  is  likely  to 
be  much  more  abundant.  It  builds  its  nest  in  low  bushes 
on  the  borders  of  swamps ;  and  in  the  West  often  appears 


RELATIONS  OF  BIRDS  TO  GARDENS  301 

in  enormous  flocks  in  grain  fields,  doing  much  damage. 
But  its  injuries  are  partly  atoned  for  by  the  fact  that  it  eats 
large  numbers  of  injurious  insects,  many  of  them  being 
grain-destroying  pests. 

In  the  Pacific  coast  region  the  Brewer  Blackbird  is 
abundant.  Its  friends  have  to  confess  that  it  is  fond  of 
cherries,  but  they  also  claim  that  it  is  a  great  destroyer 
of  insects.  When  Professor  F.  E.  L.  Beal  was  studying 
these  birds  as  they  were  eating  fruit  in  a  California  cherry 
orchard,  a  neighboring  fruit  grower  began  plowing.  "  Al- 
most immediately  every  blackbird  in  the  vicinity  was  upon 
the  newly  opened  ground,  and  many  followed  within  a  few 
feet  of  the  plowman's  heels  in  their  eagerness  to  get  every 
grub  or  other  insect  turned  out  by  the  plow." 

There  is  a  great  difference  of  opinion  about  the  economic 
relations  of  the  common  crow  —  a  bird  that  is  abundant 
over  most  of  the  United  States.  Many  people  accuse  it, 
and  with  justice,  of  pulling  up  sprouting  corn,  robbing 
birds'  nests,  and  carrying  off  young  chickens  as  well  as  of 
eating  small  wild  animals  —  such  as  toads,  frogs,  and 
snakes  —  which  are  beneficial  to  man.  To  counterbalance 
these  sins,  however,  it  is  certain  that  the  crow  destroys 
large  numbers  of  noxious  insects.  It  also  feeds  freely 
upon  various  wild  berries  and  fruits,  including  the  sumac, 
dogwood,  sour  gum,  and  poison  ivy. 

The  chief  injury  to  corn  is  done  by  the  birds  pulling  up 
the  young  plants  or  feeding  upon  the  swollen  kernels  after 
they  become  softened  by  the  moisture  of  the  soil. 

FLYCATCHERS,  SWIFTS,  AND  SWALLOWS 

A  distinct  phase  of  the  war  against  insect  pests  is  car- 
ried on  by  Flycatchers  such  as  the  Phoebe  and  the  King- 


302  FARM  FRIENDS  AND   FARM  FOES 

bird.  These  perch  upon  fences,  trees,  tall  weeds,  or  posts 
wherever  they  can  watch  the  surrounding  air  space. 
When  a  fly,  moth,  beetle  or  other  insect  comes  near,  the 
bird  sallies  forth  and  snaps  it  in  its  beak.  In  this  way 
they  get  nearly  all  their  food. 

In  the  case  of  the  Phoebe  more  than  nine  tenths  of  the 
food  consists  of  insects  and  spiders,  chiefly  those  caught 
in  the  air.  In  the  case  of  the  Kingbird  the  proportion  is 
almost  as  great.  To  a  less  extent  the  Bluebird  and  the 
Cedar  Bird  have  similar  fly-catching  habits. 

The  greater  spaces  of  the  air  over  gardens  and  culti- 
vated fields  are  patrolled  during  the  day  by  the  Swifts  and 
Swallows  and  during  the  night  by  the  Whippoorwills  and 
Nighthawks.  All  of  these  spend  hours  upon  the  wing, 
continually  catching  the  myriads  of  winged  insects  that  fly 
from  place  to  place.  The  service  thus  rendered  is  of  in- 
calculable value,  and  every  one  should  strive  to  protect 
these  feathered  friends  from  enemies  of  every  sort. 

It  is  commonly  believed  that  the  Hawks  and  Owls  are 
enemies  of  the  farmer,  to  be  destroyed  whenever  possible. 
But  the  careful  studies  and  observations  of  many  com- 
petent observers  show  that  a  majority  of  these  birds  are 
friends  whose  presence  we  could  scarcely  afford  to  lose. 
They  destroy  great  numbers  of  mice  and  insects,  and  in 
Europe  are  recognized  as  beneficial  birds. 

The  Marsh  Hawk  is  one  of  the  most  useful  birds  of 
prey,  and  deserves  man's  protection.  "Its  food,"  writes 
Dr.  A.  K.  Fisher,  "consists  largely  of  small  rodents,  such 
as  meadow  mice,  half-grown  squirrels,  rabbits,  and  ground 
squirrels."  The  stomach  of  a  New  Hampshire  specimen 
that  I  examined  was  full  of  grasshoppers. 

The  Sparrow  Hawk  is  a  small  species  that  feeds  almost 
wholly  upon  insects,  chiefly  grasshoppers,  when  these  can 


RELATIONS   OF   BIRDS   TO   GARDENS  303 

be  obtained.  In  the  sparse  pine  woods  of  southern  Florida 
I  have  found  the  Sparrow  Hawk  one  of  the  commonest 
winter  birds.  One  of  its  favorite  methods  of  obtaining 
food  there  is  to  perch  in  trees  on  the  outskirts  of  the  forest 
fires  that  frequently  occur,  and  catch  the  grasshoppers, 
lizards,  and  other  animals  driven  from  cover  by  the  flames. 


OBSERVATIONS   FOR   PUPILS 
BIRDS  IN  GARDENS  AND  FIELDS 


1.  Write  a  short  account  of  birds  that  you  have  found  in  the  yard 
and  garden  about  your  house.     Tell  what  kinds  you  have   seen  and 
what  you  have  observed  them  eating. 

2.  If  the  English  Sparrow  is  found  near  your  home,  write  a  special 
essay  about  it.     Tell  whether  it  drives  away  other  birds,  what  it  feeds 
upon,  where  the  nest  is  made,  and  how  many  broods  there  are  each 
season. 

B 

1.  Write  a  short  essay  with  this  title :     My  Favorite  Bird. 

2.  Illustrate   your  booklet  with  such  drawings  as  you  can  make, 
and  if  you  have  bird  pictures  in  magazines  or  papers  that  can  be  cut 
out,  paste  them  in  also. 

3.  Look  up  the  discussions  of  the  field  and  garden  birds  you  are 
most  interested  in  as  found  in  these  references  :  — 

The  English  Sparrow,  Farmers'  Bulletin  383.  The  Meadow  Lark  and  Balti- 
more Oriole,  Yearbook  Reprint  37,  Part  2.  The  Food  of  Nestling  Birds,  Year- 
book Reprint  194.  Birds  in  their  Relations  to  Man,  pages  156-173. 


PART   V 

FRIENDS    AND    FOES    AMONG   THE 
MAMMALS 


PRfllRE  DOO  BURROW  5KTO1AL 

FROM     ThC  BIOLOGICAL    SURVEY 


THE  BOOKLET  ON  MAMMALS 

It  will  probably  be  more  difficult  to  get  abundant  material  for  this  booklet 
than  any  other.  It  is  consequently  less  essential  that  one  should  be  made. 

The  booklet  may  well  be  made  up  largely  of  the  observations  and  experi- 
ences of  each  pupil  concerning  the  mammals  most  abundant  in  the  locality 
of  the  school.  It  may  readily  be  enriched  by  the  use  of  pictures  cut  from 
magazines  and  mounted  upon  sheets  of  drawing  paper. 


CHAPTER  XXX 
The  Squirrels 

THE  four-footed  animals  help  to  form  a  group  called  the 
Mammals.  Some  of  the  wild  mammals  are  helpful  on  the 
farm,  but  many  more  are  hurtful.  The  great  majority  of 
the  latter  belong  to  the  order  of  Rodents  or  Gnawing  Ani- 
mals, of  which  squirrels,  rats,  mice,  and  rabbits  are  familiar 
examples.  One  of  the  chief  characteristics  of  this  group 
is  the  curious  front  teeth  which  are  chisel-like  and  continue 
to  grow  as  long  as  the  owner  lives  ;  they  are  called  incisors. 
The  rodents  have  to  be  continually  gnawing  in  order  to 
keep  these  incisor  teeth  short  enough  for  comfort. 

Nearly  all  the  rodents  feed  upon  plant  materials,  and 
many  of  them  are  especially  fond  of  various  farm  and 
garden  crops.  Some,  however,  as  the  common  rat,  are 
practically  omnivorous. 

The  interesting  family  of  Squirrels  (Sciuridae)  includes 
the  True  Squirrels,  the  Marmots,  and  the  Flying  Squirrels. 
The  True  Squirrels  are  divided  into  three  groups  :  the 
Tree  Squirrels,  of  which  the  Gray  Squirrel  and  Red 
Squirrel  are  familiar  examples ;  the  Rock  Squirrels,  of 
which  the  Chipmunk  is  an  example,  and  the  Ground  Squirrels 
or  Spermophiles.  The  Marmots  include  the  Woodchuck 
and  Prairie  Dog. 

GROUND  SQUIRRELS  OR  SPERMOPHILES 

The  Ground  Squirrels  or  Spermophiles  are  now  classified 
in  the  genus  Citellus.  They  are  often  called  Gophers, 

307 


3o8  FARM   FRIENDS  AND   FARM   FOES 

although  this  much-abused  word  is  more  properly  restricted 
to  the  family  of  rodents  commonly  called  Pocket  Gophers. 
These  differ  greatly  in  structure  and  appearance  from  the 
ground  squirrels. 

The  Spermophiles  bear  a  rather  striking  general  resem- 
blance in  habits  to  the  Chipmunks.  They  are  ground-loving, 
grain-eating  squirrels,  varying  into  more  than  seventy 
species  or  subspecies  in  the  Western  regions  where  they 
occur.  They  are  known  to  cause  an  annual  loss  of  many 
millions  of  dollars,  chiefly  through  their  injuries  to  grain 
and  forage  crops.  They  have  recently  been  suspected  of 
carrying  germs  of  the  deadly  disease  known  as  bubonic 
plague,  so  that  they  may  become  a  menace  to  human  life. 

The  Leopard  Spermophile,  also  known  as  the  Thirteen- 
lined  or  the  Striped  Spermophile,  is  one  of  the  most 
abundant  and  widely  distributed  species  of  ground  squir- 
rels. It  occurs  from  Michigan  and  Minnesota  west  to 
the  Rocky  Mountains  and  south  to  Texas.  It  lives  in 
burrows  about  two  inches  in  diameter  and  not  more  than 
two  feet  below  the  soil  surface.  The  length  of  these 
burrows  varies  greatly ;  some  are  mere  pockets  for  tem- 
porary shelter,  while  others  extend  horizontally  for  many 
feet.  During  summer  the  Spermophiles  come  forth  from 
their  burrows  in  search  of  seeds  of  weeds,  grains,  grasses, 
the  succulent  root  stems  and  leaves  of  clover,  alfalfa,  and 
other  forage  crops,  as  well  as  grasshoppers  and  other  in- 
sects. All  these  materials  serve  for  food.  While  some 
benefit  to  man  is  derived  from  the  grasshoppers  destroyed, 
it  is  more  than  counterbalanced  by  the  injury  done  to 
grain,  forage,  and  other  crops. 

Early  in  autumn  the  Leopard  Ground  Squirrels  store 
up  seeds  and  grain  in  their  burrows.  When  winter  comes, 
they  fall  into  a  hibernating  sleep  that  lasts  about  five 


THE   SQUIRRELS  309 

months,  after  which  they  awake  and  feed  upon  the  stored 
seeds  and  such  other  food  as  they  can  find  outside.  Dur- 
ing this  spring  season  they  dig  up  newly  planted  corn  and 
other  seeds.  The  young  are  generally  born  in  April, 
there  being  six  to  ten  in  each  litter. 

In  Wyoming,  the  Dakotas,  and  neighboring  states  the 
Gray  Ground  Squirrel  or  Franklin's  Spermophile  is  the 
most  abundant  species.  It  bears  a  striking  resemblance  to 
the  tree-loving  Gray  Squirrel  of  the  Eastern  states.  It  feeds 
on  grain  and  forage  crops  as  well  as  upon  field  mice  and 
grasshoppers  and  other  insects.  It  has  also  a  fondness 
for  young  chickens  that  makes  it  a  troublesome  neighbor 
where  poultry  is  raised. 

In  arid  or  semiarid  regions  where  irrigation  is  practiced, 
various  species  of  ground  squirrels  do  much  damage  to  the 
irrigation  ditches  by  burrowing  into  them  and  deflecting 
the  water. 

Fortunately  for  man,  these  ground  squirrels  form  the  nat- 
ural food  of  many  predaceous  mammals  and  birds.  Such 
animals  as  coyotes,  badgers,  foxes,  and  skunks  feed  freely 
upon  them.  Hawks,  owls,  and  eagles  are  always  after 
them.  The  general  destruction  of  these  natural  enemies 
has  been  an  important  reason  for  the  increase  in  the  num- 
bers of  ground  squirrels. 

The  most  practical  means  of  destroying  these  pests  di- 
rectly is  the  use  of  poisoned  food.  Grain  or  green  alfalfa  is 
saturated  with  strychnine  and  placed  in  the  burrows.  Care 
is  always  needed,  however,  to  avoid  accidents  to  people, 
birds,  and  domestic  animals.  Precise  instructions  as  to 
the  best  methods  may  be  obtained  upon  application  to  the 
Biological  Survey,  United  States  Department  of  Agri- 
culture. 


3io  FARM   FRIENDS   AND   FARM   FOES 

MARMOTS 

The  Marmots  are  represented  in  the  United  States  by  two 
animals  of  peculiar  interest  —  the  Prairie  Dog  and  the 
Woodchuck.  These  are  grouped  in  the  squirrel  family  on 
account  of  their  general  structure,  although  different  in 
appearance  and  habits  from  the  typical  squirrels. 

The  Prairie  Dogs  inhabit  a  great  area  west  of  the  Mis- 
sissippi River  from  Texas  to  Canada.  They  are  especially 
abundant  in  prairie  regions,  where  they  often  live  in  colo- 
nies of  many  hundred  families.  Each  family  occupies  a 
burrow  having  a  mound  of  earth  at  the  entrance  to  keep 
out  water.  The  details  of  a  typical  burrow  are  shown  in 
the  diagram  on  page  306. 

The  Prairie  Dogs  feed  upon  a  variety  of  grains  and 
grasses.  They  are  troublesome  because  of  the  food  they 
consume,  the  hillocks  of  soil  they  make,  and  the  burrows 
they  dig.  They  are  preyed  upon  by  many  natural  enemies  : 
among  these  coyotes,  wolves,  foxes,  owls,  ferrets,  and  rattle- 
snakes are  the  most  important.  In  wild  regions  these 
foes  serve  to  keep  their  numbers  reduced,  but  as  land  is 
brought  into  cultivation  the  destruction  of  natural  ene- 
mies leads  to  the  increase  of  Prairie  Dogs.  They  are 
readily  destroyed,"  however,  by  placing  poisoned  grain  at 
the  mouth  of  their  burrows  or  by  the  use  of  carbon 
bisulphide. 

Nearly  every  farmer's  boy  in  the  eastern  region  of  the 
United  States  is  familiar  with  the  Woodchuck  or  "Ground- 
hog." This  is  one  of  the  largest  of  the  rodents,  and  its 
burrows  are  to  be  found  on  many  farms  in  the  hill  regions 
of  the  Northeastern  states.  It  feeds  ravenously  upon  clovers 
and  forage  crops  as  well  as  upon  beans,  peas,  cucumbers, 
and  many  other  field  and  garden  vegetables.  In  autumn 


THE   SQUIRRELS  311 

it  develops  a  thick  layer  of  fat  beneath  the  skin  and  retires 
to  the  burrow  to  hibernate. 

Woodchucks  are  commonly  trapped  or  shot,  but  the  easi- 
est way  to  kill  them  is  by  means  of  carbon  bisulphide.  A 
little  of  this  volatile  liquid  is  poured  upon  a  tuft  of  dry  moss 
or  other  absorbent  material  which  is  then  rolled  into  the 
burrow.  The  openings  are  now  closed  by  sods  or  soil,  and 
the  liquid  will  vaporize  into  a  deadly  gas  heavier  than  air. 
This  gas  will  descend  to  the  lower  portions  of  the  burrow 
to  destroy  the  animals  that  breathe  it.  If  one  is  sure  the 
burrow  is  occupied  by  a  woodchuck,  its  destruction  is  com- 
paratively certain. 

OBSERVATIONS   FOR   PUPILS 
GROUND  SQUIRRELS  OR  SPERMOPHILES 

i .  What  kinds  of  ground  squirrels,  if  any,  are  found  in  your  locality  ? 
Write  a  short  account  of  what  you  know  about  the  most  abundant 
species.  Follow  this  outline  :  — 

Size  and  color. 

Burrowing  habits. 

Feeding  habits. 

Crops  injured. 

Natural  enemies. 

Remedies,  especially  those  you  have  seen  tried. 

PRAIRIE  DOG  AND  WOODCHUCK 

1.  If  either  of  these  animals  is  common   in  your  locality,  write  a 
brief  account  under  the  headings  given  above. 

2.  Read:- 

American  Animals,  pages  151-159.  The  Destruction  of  Prairie  Dogs,  U.  S. 
Biological  Survey,  Circular  32. 


CHAPTER   XXXI 


The  Mice  and  Rats 

THE  family  of  Mice  and  Rats  is  known  by  the  technical 
name  Muridae.  It  includes  a  great  number  of  species, 
many  of  which  are  destructive  to  farm  crops.  Among  the 
well-known  members  of  this  group  are  the  muskrats, 
meadow  mice,  cotton  rats,  wood  rats,  white-footed  mice, 
and  common  rats. 

The  Short-tailed  Field  Mice,  Meadow  Mice  or  Voles,  of 
the  genus  Microtus,  are 
among  the  most  destruc- 
tive of  all  the  rodents. 
Every  farmer's  boy  is 
familiar  with  the  appear- 
ance of  these  little  ani- 
mals. Most  boys  have 
killed  many  of  them  in 
fields  or  meadows,  and  have  found  their  rounded  nests  of 
grasses  and  other  fibers. 

There  are  about  seventy  different  forms  of  Meadow 
Mice,  but  only  a  few  are  abundant  and  widely  distrib- 
uted. The  one  with  which  most  people  are  familiar  is 
called  the  Common  Meadow  Mouse,  and  is  known  techni- 
cally as  Microtus  pennsylvanicus.  This  little  creature  is 
distributed  over  most  of  the  United  States.  The  typical 
form  is  found  in  the  great  region  east  of  the  Dakotas  and 
north  of  a  line  running  through  Tennessee,  while  five 

312 


FIELD  OR  MEADOW  MOUSE 


THE   MICE   AND    RATS  313 

slightly  different  geographical  races  are  scattered  over  the 
rest  of  the  country. 

As  soon  as  the  snow  disappears  in  early  spring,  it  is  easy 
to  find  the  winter  runways  of  the  Common  Meadow  Mouse 
in  almost  any  low  grassland.  They  often  cover  the  sur- 
face with  an  interlacing  network  that  shows  how  indus- 
triously the  mice  have  been  at  work  beneath  the  snow. 
Should  you  follow  up  these  runways  carefully,  you  would 
probably  come  to  shelter  nests  made  of  grasses  which 
served  for  temporary  quarters  through  the  winter.  And 
if  you  should  explore  late  in  spring  or  in  the  summer,  you 
would  often  find  holes  leading  to  the  underground  nests  in 
which  the  young  are  reared.  The  nests  are  likely  to  be 
lined  with  the  soft  silk  from  the  milkweed  pods  or  the  silky 
seeds  of  cat-tail  flags. 

Meadow  mice  find  their  safest  home  along  the  borders  of 
swamps  or  other  lowlands  or  in  neglected  meadows  where 
there  is  a  rank  growth  of  grass.  The  shelter  of  the  grass 
protects  them  from  enemies  and  enables  them  to  forage 
far  and  wide.  It  also  serves  for  warmth  in  winter  and 
furnishes  abundant  material  for  nest  building.  When  the 
snow  is  deep,  however,  the  mice  tunnel  beneath  it  in  all 
directions,  seeking  orchards  and  grain  fields  where  food 
may  be  found. 

In  the  matter  of  food  the  meadow  mice  are  not  very  par- 
ticular. They  will  eat  almost  any  succulent  vegetable  mate- 
rial. They  are  especially  fond  of  the  swollen  roots  of  the 
wild  white  morning  glory,  large  numbers  of  which  are  often 
stored  in  underground  piles.  David  E.  Lantz  once  found 
a  pile  of  these  thus  stored  away  that  weighed  more  than 
a  pound.  The  roots,  stems,  leaves,  and  seeds  of  most 
vegetable,  forage,  and  grain  crops  are  freely  eaten.  In 
winter  they  find  the  bark  of  trees  and  shrubs  one  of  the 


314  FARM   FRIENDS   AND    FARM   FOES 

chief  sources  of  food,  and  in  consequence  they  often  do 
great  damage  in  orchards,  especially  those  recently  set. 
Trees  of  good  size  are  girdled,  while  small  ones  may  have 
the  bark  nearly  all  torn  off  the  trunk.  As  this  is  done  in 
winter  under  shelter  of  the  snow,  the  owner  may  not  sus- 
pect any  damage  until  it  is  revealed  in  spring. 

The  Common  Meadow  Mouse  multiplies  very  rapidly. 
The  average  is  about  four  litters  of  young  each  year  with 


Wild  Morninq-qlory  Roots  Stored  by  Meadow  Mice 

about  six  in  each  litter.  It  has  been  estimated  that  if  there 
were  no  destruction  by  enemies,  "a  single  pair  and  their 
progeny  in  five  seasons  would  amount  to  nearly  1,000,000 
individuals."  This  of  course  does  not  happen  because 
many  are  killed  in  various  ways,  but  the  estimate  shows 
how  rapidly  these  pests  multiply  under  favorable  condi- 
tions. It  also  indicates  the  necessity  of  providing  as  many 
natural  checks  upon  their  increase  as  possible. 

In  the  great  prairie  regions  of  the  Middle  West  the 
Prairie  Mouse  is  abundant  and  destructive  to  a  great 
variety  of  crops.  It  is  distinguished  from  the  Common 
Meadow  Mouse  chiefly  by  its  shorter  tail,  which  is  not 
much  longer  than  the  hind  foot. 

The  Prairie  Mouse  is  most  likely  to  develop  in  neglected 
fields  and  meadows,  from  which  it  scatters  into  surround- 
ing localities.  In  range  pastures  that  are  not  closely 
grazed,  these  mice  are  likely  to  develop  in  grassy  tufts 


THE   MICE   AND    RATS 


315 


neglected  by  the  stock.  In  orchards  that  are  allowed  to 
grow  up  to  weeds  and  grasses,  they  are  also  likely  to  de- 
velop in  such  abundance  as  to  injure  the  trees  seriously 
by  gnawing  the  bark.  They  are  often  destructive  to  young 

trees  in   nurser-   . 

ies,  especially 
where  clean  cul- 
ture is  not  given. 

The  rate  of 
reproduction 
of  the  Prairie 
Mouse  is  slightly 
less  than  that  of 
the  Common 
Meadow  Mouse, 
there  being 
fewer  young  in 
each  litter.  The 
climatic  condi- 
tions as  to 
drought  in  sum- 
mer and  cold  in  winter,  and  the  less  general  presence  of 
sheltering  materials,  also  tend  to  check  its  increase.  But 
it  often  becomes  far  too  abundant  and  destructive. 

The  runways  of  the  Prairie  Mouse  and  the  Common 
Meadow  Mouse  are  generally  made  above  the  soil  surface, 
though  commonly  beneath  the  shelter  of  overhanging  grasses 
or  other  vegetation.  This  is  an  easy  way  to  distinguish 
them  from  the  nearly  related  Pine  Mouse,  which  makes  its 
molelike  runways  through  the  soil  itself. 

This  Pine  Mouse  in  the  typical  form  or  that  of  a  closely 
allied  geographical  race,  is  distributed  over  most  parts  of 
the  United  States.  It  makes  its  home  in  woodlands  rather 


HYACINTH  BULBS  EATEN  BY  PINE  MICE 


316  FARM  FRIENDS  AND   FARM  FOES 

than  in  open  fields,  but  it  habitually  invades  the  latter  in 
search  of  food.  Its  journeys  are  made  just  beneath  the 
surface  of  loose  soil,  in  a  manner  very  similar  to  that  of  the 
true  mole,  for  which  these  mice  are  frequently  mistaken. 
They  feed  upon  a  great  variety  of  roots,  tubers,  and  bulbs, 
often  destroying  crops  in  such  a  way  that  the  injury  is  not 
suspected  until  long  afterward.  They  seem  especially  fond 
of  the  tuberous  roots  of  wild  violets  which  are  often  stored 
up  in  piles  in  underground  galleries. 

NATURAL  ENEMIES 

Under  natural  conditions  the  rapid  development  of 
meadow  mice  is  counterbalanced  by  the  fact  that  they 
furnish  a  large  part  of  the  food  of  many  carnivorous  mam- 
mals and  raptorial  birds.  Next  to  insects,  mice  are  the 
most  important  item  in  the  food  of  skunks.  They  form  the 
principal  food  of  weasels  and  a  large  part  of  the  food  of 
badgers  and  foxes. 

There  is  little  doubt,  however,  that  the  raptorial  birds 
are  the  principal  natural  enemies  of  the  voles.  Hawks  and 
owls  of  many  kinds  find  in  these  short-tailed  mice  their 
most  important  food.  This  is  especially  true  of  the  Marsh 
Hawk  and  the  so-called  Buzzard  Hawks  of  the  genus 
Buteo.  The  latter  include  the  Red-tailed,  Red-shouldered, 
and  Broad-winged  Hawks.  These  are  a  comparatively  large 
and  heavy  species  that  find  field  mice  an  easy  prey.  The 
Biological  Survey  found  three  hundred  and  fifty  of  these 
mice  among  the  stomach  contents  of  two  hundred  and 
twenty-eight  Red-tailed  Hawks. 

In  comparison  with  their  number,  the  owls  seem  even 
more  useful  as  mice  destroyers  than  the  hawks.  These 
birds  are  abroad  at  night  when  the  meadow  mice  are  most 


THE   MICE   AND   RATS  317 

active.  They  are  able  to  fly  noiselessly  over  fields  and 
through  woods  and  to  gather  their  prey  quickly  in  their 
hooked  talons.  Practically  all  the  owls  feed  largely  upon 
field  mice,  and  several  of  them,  notably  the  Screech  Owl 
and  the  Long-eared  Owl,  find  in  them  their  chief  source 
of  food. 

It  has  often  happened  that  in  certain  regions  the  natural 
enemies  of  the  voles  have  been  so  persecuted  as  to  become 
scarce.  When  the  checks  upon  their  increase  are  thus  re- 
moved, the  voles  multiply  with  alarming  rapidity  and 
become  exceedingly  destructive.  When  this  occurs,  the 
hawks  and  owls  from  surrounding  regions  are  attracted 
to  the  infested  locality,  where  they  remain  to  feast  upon 
the  mice.  These  raptorial  birds  are  thus  like  a  standing 
army  that  nature  moves  from  place  to  place  to  subdue  in- 
surrections. It  is  very  foolish  for  man  to  wage  war  upon 
this  army  ;  he  often  has  occasion  to  regret  such  persecution. 

Various  other  birds  are  also  useful  as  destroyers  of 
meadow  mice.  Crows,  ravens,  and  magpies  feed  upon  them, 
especially  the  young  mice.  Shrikes  destroy  great  numbers. 
Herons,  bitterns,  cranes,  and  gulls  also  feed  upon  them. 

REMEDIAL  MEASURES 

The  ways  in  which  farmers  may  aid  in  keeping  meadow 
mice  below  the  danger  line  are  many.  One  of  the  most 
effective  is  by  protecting  the  natural  enemies  of  the  voles. 
Another  is  that  of  clean  culture  of  the  places  where  the 
mice  breed  and  the  tillage  of  infested  fields.  Much  help 
can  also  be  obtained  from  cats  and  dogs  that  are  good 
mousers  and  from  close  grazing  by  the  larger  domestic 
animals. 

The  chief  means  of  direct  destruction  of  the  meadow 
mice  are  traps  and  poisons.  The  so-called  guillotine  traps 


318  FARM  FRIENDS  AND   FARM   FOES 

made  of  coiled  wire  are  useful  if  placed  in  the  runways, 
either  baited  or  unbaited,  but  they  require  constant  atten- 
tion. A  single  hawk  left  in  peace  is  likely  to  do  the  work 
of  many  traps.  Poisons  may  also  be  employed,  but  these 
should  be  used  by  persons  of  mature  judgment  on  account 
of  the  danger  of  injury  to  children,  domestic  animals,  and 
friendly  birds.  Specific  instructions  as  to  the  best  poisons 
and  their  use  may  be  obtained  from  the  Biological  Survey, 
Washington,  D.C.  In  some  states  the  use  of  poisoned  baits 
is  prohibited  by  law. 

The  injury  done  by  meadow  mice  to  trunks  of  trees  may 
generally  be  prevented  by  protecting  the  trunk  with  a 
wrapping  of  wire  screening  or  some  other  tree  protector. 
In  many  states  wood  veneer  protectors  are  used  to  prevent 
injury  by  "  sun  scald  "  as  well  as  mice.  There  is  much 
evidence,  also,  to  indicate  that  a  simple  application  of  the 
lime-sulphur  wash  used  against  the  San  Jose  scale  is  an 
efficient  protection.  Tramping  down  the  snow  next  the 
trees  also  saves  them  from  injury,  but  this  is  not  always 
practicable. 

WHITE-FOOTED  MICE 

There  are  many  species  and  varieties  of  the  White- 
footed  Mouse,  which 
perhaps  is  the  most 
beautiful  member  of 
the  family.  They  are 
all  alike  in  having  the 
lower  parts  of  the 
body  as  well  as  the 
legs  and  feet  of  a 
white  color  that  con- 
WHITE-FOOTED  OR  DEER  MOUSE  trasts  strikingly  with 


THE   MICE   AND    RATS 


the  gray  above.  They  live  in  woods  and  fields,  making 
their  nests  in  logs,  hollow  trees,  sheds,  boxes,  and  almost 
every  other  available  place. 
On  the  Western  plains  they 
often  nest  in  the  bleaching 
buffalo  skulls.  They  are  not 
so  distinctly  injurious  as  are 
the  meadow  mice,  though 


they   often    become 
troublesome. 

THE  RATS 


locally 


CORNSTALK  RUINED  BY  BROWN- 
RATS 


There  is  little  need  to  di- 
rect attention  to  the  common 
Brown  Rat,  doubtless  the 
most  destructive  species  of 
rodent  in  the  United  States. 
It  is  so  because  of  its  large 
size,  its  omnivorous  feeding 
habits,  its  rapid  multiplica- 
tion, and  its  ability  to  penetrate  through  most  obstacles. 
The  young  mature  in  six  months,  and  three  or  four 
litters  are  born  a  year,  each  lit- 
ter consisting  of  from  six  to  a 
dozen. 

Rats  are  destructive  in  fields,  gar- 
dens, barns,  cellars,  storage  sheds, 
and  houses.  They  feed  on  all  sorts 
of  vegetable  and  animal  products, 
dead  or  alive.  They  carry  germs 

RAT  TRAP  USED  IN  BURMA 

of     diseases,     and     are     altogether 

most  pestiferous  creatures.     War  should  be  waged  upon 
them  in   every  practicable  way,  and  buildings  should  be 


320  FARM   FRIENDS  AND   FARM   FOES 

so  concreted  in  cellar  and  basement  as  to  prevent  their 
entrance. 

Many  good  traps  for  rats  are  now  available.  The  so- 
called  guillotine  trap  is  perhaps  the  best.  It  is  on  sale 
in  various  forms  in  hardware  stores.  Each  trap  should 
be  thoroughly  scalded  after  use,  in  order  to  catch  new 
victims.  Two  ingenious  forms  of  rat  traps 
are  shown  in  the  accompanying  pictures. 
The  form  used  in  Burma  is  a  large  earth- 
enware vessel  closed  at  the  top  by  a  board 
held  in  place  by  a  heavy  stone.  The  rats 
go  in  the  small  hole  shown,  and  are  unable 
to  get  out.  Rice  or  other  bait  is  put  in 
the  bottom  of  the  jar.  The  barrel  trap  is 

BARREL  TRAP      readily  understood   from  the  picture :  the 
FOR  RATS 

bait  is  fastened  in  place  at  b ;    a  cleat  is 

nailed  on  at  a  to  hold  the  hinged  top  from  going  down  on 
that  side. 

OBSERVATIONS  FOR  PUPILS 

MEADOW  MICE 

1.  Observe  the  runways  of  these  mice,  especially  in  early  spring. 
Do  you  find  any  holes  that  go  deeper  in  the  ground  ? 

2.  Look  for  trees  and  shrubs  in  which  the  bark  has  been  gnawed 
off  by  meadow  mice.     Make  a  list  of  the  kinds  of  trees  and  shrubs. 

3.  What  methods  of  preventing  damage  by  these  pests  have  you 
known  to  be  tried? 

Read :  — 
Meadow  Mice  in  Relation  to  Agriculture,  Yearbook  Reprint  388. 

RATS  AND  MICE 

1.  How  can  you  distinguish  a  rat  from  a  mouse? 

2.  What  damage  have  you  known  rats  to  do? 

3.  What  ways   have  you  tried  to  destroy  rats  ? 
Read :  - 

How  to  Destroy  Rats,  Farmers'  Bulletin  369. 


CHAPTER   XXXII 
The  Rabbits,  Pocket  Gophers,  Moles,  and  Shrews 

THE  Rabbits  probably  rank  next  to  the  meadow  mice  as 
widespread  destroyers  in  field,  garden,  and  orchard.  In 
the  region  east  of  the  Great  Plains  the  familiar  Cottontail 
or  Gray  Rabbit  is  abundant.  In  the  Northern  states  the 
Varying  Hare  or  Northern  Rabbit  is  found.  In  the  West 
some  form  of  the  large  Jack  Rabbit  occurs,  as  well  as  vari- 
ous sorts  of  Cottontail  Rabbits.  Consequently,  rabbits 
are  found  over  the  whole  United  States,  and  do  injury 
wherever  abundant. 

The  damage  done  by  Rabbits  is  due  to  their  voracity  and 
abundance.  They  require  large  amounts  of  food  and 
multiply  rapidly.  They  eat  plant  products  exclusively, 
including  bark,  branches,  buds,  leaves,  flowers,  fruits,  and 
seeds.  Wheat,  oats,  barley,  corn,  clovers,  alfalfa,  and  other 
grains  and  grasses  are  destroyed  in  the  field.  Peas,  beans, 
cabbage,  melons,  and  other  vegetables  are  destroyed  in  the 
garden.  Bark,  twigs,  shrubs,  and  young  trees  are  devoured 
in  the  orchard  and  nursery. 

With  so  varied  a  food  supply,  Rabbits  naturally  prefer 
the  more  tender  and  succulent  products.  Consequently, 
grain,  forage,  and  garden  crops,  or  fallen  fruits  are  most 
commonly  eaten,  bark,  twigs,  and  other  less  edible  things 
being  attacked  chiefly  in  winter  or  in  seasons  of  drought. 
The  chief  injury  to  orchard  trees  occurs  in  winter,  when 
the  bark  is  stripped  off  in  a  characteristic  manner. 

In  the  Western  alfalfa  fields  Rabbits  are  often  very 

321 


322  FARM   FRIENDS  AND   FARM   FOES 

destructive,  congregating  in  large  numbers  in  isolated 
fields  and  ruining  the  crop.  In  the  great  melon-growing 
regions  they  often  cause  the  loss  of  crops  by  destroying 
young  cantaloupe  and  watermelon  plants,  and  in  gardens 
everywhere  they  are  especially  destructive  to  peas  and 
cabbage.  The  greatest  damage  in  orchards  is  likely  to  be 
done  to  comparatively  young  trees,  although  in  many  apple- 
growing  regions  Rabbits  are  recognized  as  a  pest  always  to 
be  guarded  against. 

The  strong  hind  feet  are  the  only  weapons  of  offense 
with  which  the  rabbits  are  provided,  but  their  structure, 
habits,  and  instincts  enable  them  to  escape  to  a  large 
extent  the  attacks  of  their  many  enemies.  With  keen  eyes 
so  set  in  the  head  as  to  include  a  large  field  of  vision,  with 
large  ears  to  detect  the  slightest  sound,  with  a  coloring 
that  makes  them  almost  invisible  amid  their  natural  sur- 
roundings, accompanied  by  an  instinct  to  keep  quiet  most 
of  the  time,  and  .with  long  legs  adapted  to  rapid  running, 
rabbits  are  well  equipped  in  their  struggle  for  life.  For- 
tunately for  mankind,  however,  many  of  their  natural 
enemies  are  able  to  penetrate  their  disguises  or  overtake 
them  as  they  run,  so  that  rabbits  furnish  food  for  a  consid- 
erable number  of  mammals  and  birds.  Wolves,  foxes, 
wild  cats,  badgers,  weasels,  and  other  carnivorous  mammals 
live  largely  upon  rabbits,  while  practically  all  the  larger 
hawks  and  owls  prey  freely  upon  them.  In  wild  regions 
these  various  natural  enemies  serve  an  important  purpose 
in  keeping  a  balance  in  rabbit  life,  but  in  cultivated  regions 
such  enemies  often  become  so  scarce  as  to  be  less  important. 
As  people  learn  the  real  value  of  certain  hawks  and  owls 
as  destroyers  of  rabbits,  mice,  and  other  mammals,  they 
will  probably  learn  to  discriminate  between  friends  and  foes 
among  birds  of  prey. 


RABBITS  AND  POCKET  GOPHERS 


323 


Fortunately,  rabbits  are  good  for  food,  and  in  most  regions 
hunting  is  the  chief  means  of  keeping  them  in  check.  In 
localities  where  jack  rabbits  are  very  abundant,  many 
people  sometimes  combine  to  make  a  "rabbit  drive"  in 
which  practically  all  the  rabbits  for  miles  around  are  driven 
into  a  wire  fence  inclosure  where  they  are  killed  by  the 
thousand. 

Fortunately,  also,  rabbits  are  easily  trapped.  Most  coun- 
try boys  have  caught  them  in  the  figure-four  traps.  The 
Wellhouse  trap 
is  an  improve- 
ment upon  this 
and  is  readily 
made  by  follow- 
ing the  direc- 
tions at  the  end 
of  this  chapter. 
In  large  or- 
chards two  or 
three  such  traps  to  each  acre  of  trees  will  keep  the  rab- 
bits in  check  so  that  little  or  no  damage  will  be  done  by 
them. 

Rabbits  are  also  destroyed  by  poisons,  but  this  method 
should  only  be  used  by  men  who  will  see  that  there  is  no 
possibility  of  harm  to  children,  domestic  animals,  or  useful 
birds.  Injuries  to  trees  are  prevented  by  guards  of  wire 
screening  placed  around  the  trunk.  Various  washes  are 
also  helpful  in  preventing  damage  to  trees.  One  of  the 
best  of  these  is  the  lime-sulphur  wash  used  to  destroy 
the  San  Jose  scale.  A  liberal  spraying  or  brushing  of 
the  bark  with  this  late  in  autumn  is  a  protection  for  the 
winter. 


DETAILS  OF  WELLHOUSE  RABBIT  TRAP 


324  FARM   FRIENDS  AND   FARM   FOES 

POCKET  GOPHERS 

The  Pocket  Gophers  of  the  family  Geomyidse  form  one 
of  the  most  vexatious  groups  of  rodents.  They  are  rather 
small  molelike  creatures  with  a  marvelous  ability  to  dig 
their  way  through  loose  soil.  They  live  in  underground 
burrows  and  feed  upon  the  roots  of  trees,  vegetables,  and 
forage  crops,  as  well  as  the  leaves  of  many  plants.  They 
are  especially  destructive  to  potatoes  and  in  alfalfa  fields. 

The  various  species  of  Pocket  Gophers  found  in   the 


GEORGIA  GOPHER 

United  States  occur  chiefly  in  the  region  west  of  the 
Mississippi  River,  though  one  is  found  in  Georgia,  Alabama, 
and  Florida,  and  another  in  Wisconsin  and  Illinois.  The 
Prairie  Gopher  is  one  of  the  most  destructive  species,  as  it 
inhabits  the  fertile  region  of  the  Mississippi  Valley.  The 
Plains  Pocket  Gopher  occurs  in  more  arid  regions  west,  and 
the  Gray  Pocket  Gopher  is  even  more  widely  distributed 
over  both  prairies  and  plains. 

The  structure  of  the  Pocket  Gophers  admirably  adapts 
them  to  their  underground  life.  The  bodies  are  thickly 
clothed  with  fine  hair  that  repels  moisture  and  earth  ;  the 
heads  are  pointed,  the  eyes  and  ears  are  small,  the  front 
feet  are  especially  adapted  to  digging,  and  the  tail  is  so 


RABBITS  AND  POCKET  GOPHERS      325 

sensitive  that  it  is  used  as  an  organ  of  touch,  when  the 
gopher  runs  backward  through  the  burrows  —  a  habit 
that  saves  much  trouble  in  turning  round.  Among  the 
most  notable  points  of  structure  are  the  remarkable  cheek 
pouches  that  open  externally. 

As  these  gophers  make  their  horizontal  burrows,  they 
get  rid  of  the  soil  by  making  holes  to  the  surface  every  few 
feet  through  which  the  loose  earth  is  pushed  out  to  form  a 
little  mound.  The  hole  to  the  mound  is  finally  filled  up 
and  another  made  farther  along.  In  meadows  and  fields 
of  forage  crops  these  mounds  sometimes  make  it  neces- 
sary to  run  the  mowing  machines  several  inches  above  the 
surface  of  the  soil,  thereby  preventing  the  harvesting  of 
much  of  the  crop.  This  is  one  of  the  most  troublesome 
effects  of  the  work  of  gophers. 

The  Pocket  Gophers  work  so  constantly  underground 
that  they  have  comparatively  few  natural  enemies.  They 
come  to  the  surface  oftener  by  night  than  by  day,  so  that 
the  owls  catch  more  than  the  hawks.  Other  enemies  are 
weasels,  and  bull  or  gopher  snakes.  Each  of  these  enter 
the  burrows  and  follow  along  till  they  find  their  victims. 
'  Fortunately,  the  Gophers  can  be  rather  easily  killed  by 
the  use  of  poisons  without  much  danger  to  other  animals. 
By  punching  a  hole  down  to  the  burrow,  with  an  old  spade 
handle  having  a  pointed  metallic  tip,  one  can  make  an 
opening  through  which  small  pellets  of  poisoned  food  can 
be  inserted  in  the  main  runways,  where  there  will  be  little 
danger  of  their  being  eaten  by  other  animals.  Such  pellets 
should  net  be  placed  near  the  mouth  of  a  burrow,  because 
of  the  danger  of  its  being  exposed  where  some  other  ani- 
mal might  get  it.  Strychnine  is  the  poison  most  commonly 
used,  and  the  prepared  poison  pellets  are  on  sale  in  many 
drug  stores.  Great  care  is,  of  course,  necessary  in  han- 


326  FARM   FRIENDS  AND   FARM  FOES 

dling  this  deadly  poison ;  special  pains  should  always  be 
taken  that  none  of  the  poisoned  materials  be  left  within 
the  reach  of  children. 

These  pests  may  be  caught  in  traps  placed  in  the  burrows. 
Various  forms  of  traps  for  this  purpose  are  now  upon  the 
market.  Gophers  may  also  be  killed  by  the  use  of  carbon 
bisulphide,  a  volatile  liquid  that  rapidly  vaporizes  when 
placed  in  the  burrow.  The  vapor  is  a  deadly  poison  and 
soon  kills  any  animal  that  breathes  it.  It  is  also  inflam- 
mable, and  no  fire  must  be  brought  near  it. 

MOLES  AND  SHREWS 

There  is  a  small  order  of  mammals  called  the  Insectivora 
or  Insect-eaters.  It  includes  the  Moles  and  Shrews.  These 
animals  live  mostly  in  underground  burrows  and  are 
seldom  seen  except  when  turned  over  by  accident.  The 
burrows  of  Moles  are  familiar  to  many  people,  though 
doubtless  the  burrows  of  Pine  Mice  are  often  mistaken  for 
them.  Moles  feed  largely  upon  earthworms  and  under- 
ground insects,  but  are  also  often  troublesome  when  they 
make  their  runways  through  lawns  and  gardens. 

In  the  great  order  Carnivora  or  Flesh-eaters  are  found 
many  of  the  large  wild  mammals,  such  as  bears,  wolves, 
coyotes,  foxes,  and  badgers,  as  well  as  a  number  of  smaller 
ones,  such  as  weasels  and  ferrets.  Many  of  these  are 
efficient  checks  upon  destructive  rodents,  but  there  is 
comparatively  little  help  to  be  expected  from  them  in 
thickly  settled  regions. 

MAKING  THE  WELLHOUSE  TRAP 

The  following  directions  for  making  this  excellent  rabbit 
trap  are  given  by  David  E.  Lantz :  — 


RABBITS  AND   POCKET   GOPHERS  327 

"  The  trap  is  a  box  made  of  6-inch  fencing  boards,  old 
ones  being  preferred.  The  box  is  about  21  inches  long, 
closed  at  the  back  by  a  board,  but  in  front  by  a  wire  door 
only.  The  door  is  hung  from  the  top  and  swings  inward. 
A  cleat  at  the  bottom  prevents  its  opening  outward.  The 
trap  is  set  and  the  wire  door  is  kept  open  by  a  wire  trigger 
rod,  held  in  place  by  two  staples  fastened  to  the  top  of  the 
box.  This  trigger  is  bent  downward  near  the  rear  of  the 
trap  and  formed  into  a  loop  or  a  figure  eight.  As  the  rab- 
bit enters  the  trap  and  crowds  into  the  back  part,  it  pushes 
upon  the  loop,  moves  the  trigger  wire  backward,  and  releases 
the  wire  door.  This  falls  and  makes  the  rabbit  a  prisoner. 
Bait  may  be  used,  but  is  not  necessary,  since  the  cottontail 
is  constantly  looking  for  dark  places  to  hide  from  enemies 
or  cold  winds.  Mr.  Wellhouse  uses  about  three  traps  per 
acre  in  young  orchards  and  many  among  the  bearing  trees. 
They  are  regularly  looked  after  by  boys,  and  so  effective 
have  they  proved  that  no  serious  losses  from  rabbits  have 
occurred  in  his  orchards. 

"  The  materials  needed  for  making  a  Wellhouse  trap  are  : 
Four  boards  I  by  6,  2 1  inches  long ;  one  piece  I  by  6,  8 
inches  long  for  the  back  ;  a  short  cleat  for  the  door  stop  ; 
28\  inches  of  wire  to  serve  for  the  door  ;  22  inches  of  wire 
for  the  trigger ;  four  small  staples  for  hanging  the  door 
and  trigger  ;  and  nails." 


OBSERVATIONS   FOR  PUPILS 

1 .  Write  or  tell  a  story  with  this  title  :     What  I  know  about  Rabbits. 

2.  Read:  — 

The  Rabbit  as  a  Farm  and  Orchard  Pest,  Yearbook  Reprint  452;  The  Story  of 
Raggylug  in  Wild  Animals  I  have  Known* 


BIBLIOGRAPHY 

Teachers  or  pupils  may  obtain  the  various  Farmers'  Bulletins  and 
other  publications  of  the  United  States  Department  of  Agriculture 
referred  to  in  connection  with  the  Observations  for  Pupils  free  of  charge 
on  application  to  the  Secretary  of  Agriculture.  Each  school  should  have 
a  set  of  the  recent  issues  of  the  Yearbook  of  the  Department  and  of  the 
Yearbook  Reprints  referred  to  in  these  pages. 

A  set  of  the  bulletins  of  the  State  Experiment  Station  should  also  be 
on  file  for  reference,  with  extra  copies  of  such  as  are  especially  useful  in 
connection  with  the  subjects  studied. 

The  following  books  are  referred  to  in  connection  with  reading  for 
pupils.  They  may  be  purchased  through  any  book  dealer. 

INSECTS 

DICKERSON  :  Moths  and  Butterflies. 

HOWARD  :  The  Insect  Book. 

KELLOGG  :  American  Insects. 

MURTFELDT  AND  WEED  :  Stories  of  Insect  Life. 

PECKHAM  :  The  Solitary  Wasps. 

WEED  :  Life  Histories  of  American  Insects. 

WEED  :  Nature  Biographies. 

FUNGI 
DUGGAR  :  Fungous  Diseases  of  Plants. 

BIRDS  AND  MAMMALS 

ECKSTORM  :  The  Bird  Book. 
FORBUSH  :  Useful  Birds  and  their  Protection. 
SETON  :   Wild  Animals  I  have  Known. 
STONE  AND  CRAM  :  American  Animals. 
WEED  AND  DEARBORN  :  Birds  in  their  Relations  to  Man. 

328 


INDEX 


Acridiidae,  67. 
Aleyrodes,  273. 
Ambush  bugs,  167. 
Andrenidae,  203. 
Anthracnose,  bean,  255. 

cotton,  256. 

raspberry,  256. 
Ants,  169,  173. 

and  aphides,  92. 
Aphides,  87,  95,  187. 
Aphidius,  179. 
Aphis,  apple,  91. 

corn-root,  92. 

cotton,  oo. 

dock,  91. 

European  grain,  89. 

melon,  91. 

orange,  91. 

spring-grain,  87. 
Aphis  lions,  171. 
Apidae,  203. 
Apina,  203. 
Apple  blossom,  195,  210. 

bitter  rot,  246. 

maggot,  125. 

scab,  245. 

of  Peru,  41. 
Army  worm,  107,  188. 
Ascomycetes,  242. 
Ascospore  fungi,  242. 
Asilidae,  166. 
Aspen,  25. 
Assassin  bugs,  168. 
Asters,  wild,  20,  23. 

Bacillus  amylivorus,  259. 
Bacteria,  nitrifying,  275. 

nitrogen-gathering,  276. 

symbiotic,  278. 


Bacterial  diseases,  259,  273= 
Bacteriosis,  bean,  263. 

melon,  263. 
Bark  lice,  82,  95. 
Barley,  mouse,  15. 

wild,  15. 

Barnyard  grass,  33. 
Bean  blight,  263. 
Bees,  203. 
Beetle,  asparagus,  136. 

Colorado  potato,  135. 

cucumber,  137. 

May,  131,  147. 
Beetles,  131. 

click,  134. 

flea,  139. 

ground,  164. 

ladybird,  165. 

Lamellicorn,  132. 

leaf,  135. 

long-horn,  140. 

predaceous,  164. 

snapping,  134. 

tiger,  164. 
Beggar  ticks,  19. 
Bermuda  grass,  61. 
Billbugs,  143. 
Bindweed,  black,  42. 

hedge,  41. 
Birch,  gray,  25. 
Bird's-eye  rot,  256. 
Bitter  rot,  246. 
Blackbird,  Brewer,  300. 

crow,  300. 

redwinged,  300. 
Black  knot,  242,  257. 
Black  rot,  251. 
Blattidae,  70. 
Bluebird,  298. 


329 


330 


INDEX 


Blue-grass,  flat-stemmed,  14. 
Bobolink,  293. 
Bollworm,  in. 
Bombycine  moths,  102,  120. 
Borer,  apple-tree,  140. 

locust,  140. 
Bottle-grass,  32. 
Bouncing  Bet,  10. 
Bracken,  24. 
Brake  fern,  24. 
Brown  rot,  247. 
Buckwheat,  wild,  42. 
Buffalo  bur,  39. 
Bumblebees,  204. 
Burdock,  7. 
Bur  marigold,  19. 
Butter-and-eggs,  10,  u. 
Buttercups,  24. 
Butterflies,  97,  119. 
Butterfly,  Asterias,  97. 

black  swallowtail,  97. 

cresphontes,  98. 

mourning  cloak,  98. 

Cabbage  butterfly,  97,  186. 

clubroot,  257. 

maggot,  127. 

rot,  261. 

worm,  97,  186. 
Carabidae,  164. 
Caraway,  n. 
Carnivora,  320. 
Carrot,  small,  21. 

wild,  20. 
Catbird,  299. 
Caterpillar  fungi,  272. 
Cecidomyiidae,  123. 
Cedar,  red,  25. 
Cerambycidae,  140. 
Chalcid  flies,  152,  182. 
Charlock,  33,  47. 
Cheat  grass,  45. 
Cherry,  black,  28, 

choke,  28. 

flower,  194. 
Chess,  45- 


Chick  weed,  mouse-ear,  34. 

smooth,  34. 
Chicory,  n. 
Chinch  bug,  75. 

fungus,  76. 
Chondrilla,  19. 
Chrospidae,  171. 
Chrysomelidae,  135. 
Cicada,  dog-day,  78. 

periodical,  78. 
Cicadidae,  77. 
Cicindelidae,  164. 
Cinquefoil,  common,  23. 

Norwegian,  23. 

silvery,  23. 
Clotbur,  38. 
Clover-seed  midge,  124. 
Clubroot,  cabbage,  257. 
Coccidae,  82. 
Cockle,  49. 
Cocklebur,  38. 
Cockroaches,  70. 
Codling  moth,  113. 
Coleoptera,  131. 
Cone-flower,  19. 
Corn  cockle,  49. 

rootworm,  northern,  137. 
southern,  138. 

rust,  238. 

smut,  228,  230. 

stalk-borer,  112. 

worm,  in. 
Cotton  boll  weevil,  144,  148. 

rot,  203. 

wilt,  251. 
Couch-grass,  14. 
Cowbane,  spotted,  27. 
Crab-grass,  33. 
Crane  flies,  125. 
Crazy  weed,  26. 
Cricket,  black,  69. 

mole,  70. 

tree,  70. 

Cross-fertilized  flowers,  199. 
Crow,  293. 
Crown  gall,  261. 


INDEX 


331 


Currant  worm,  150,  153. 
Cutworms,  109. 
Cynipidae,  152. 
Cypress  spurge,  10. 

Daisy,  oxeye,  16. 
Dandelion,  3. 
Day  lily,  10. 
Diptera,  122,  188,  207. 
Dock,  bitter,  8. 

broad-leaved,  8,  59. 

curled,  8. 

sour,  8. 

yellow,  8. 
Dodder,  53. 
Dragon  flies,  170. 

Elaters,  134. 
Elecampane,  10. 
Entomophthoreae,  271. 
Evening  primrose,  9. 

False  flax,  49. 
Fern,  brake,  24. 

cinnamon,  24. 

flowering,  24. 

interrupted,  24. 

sensitive,  24. 

Fertilization  of  flowers,  194. 
Finger-grass,  33. 
Fireweed,  9. 
Five-fingers,  23. 
Flea-banes,  19. 
Flea  beetles,  139. 
Flies,  two-winged,  122,  188,  207. 
Fly-away -grass,  32. 
Foxtail,  green,  32. 

yellow,  32. 
Fruit  maggots,  125. 
Fungicides,  267. 

Gallflies,  152. 
Gallfly,  blackberry,  152. 
Gall  gnats,  123. 
Gill-over-the-ground,  44. 
Goldenrods,  23,  61. 
Goosefoot,  35. 


Gophers,  307. 

Georgia,  324. 

pocket,  324. 
Crackle,  bronzed,  300. 

purple,  300. 
Grape  mildew,  223. 
Grape  rot,  black,  251. 
brown  223. 
Grape  slug,  151. 
Grasshopper,  meadow,  69,  72. 

structure  of,  65. 
Ground  cherries,  40. 
Ground  squirrels,  307,  312. 
Gryllidae,  69. 
Gypsy  moth,  103. 

Hardback,  13,  25,  62. 
Harlequin  cabbage  bug,  77,  94. 
Harvest  fly,  78. 
Hawk,  marsh,  302. 

moths,  101,  208. 

sparrow,  202. 
Hawkweed,  orange,  17. 
Hemiptera,  73. 
Hessian  fly,  123,  129. 
Honeybees,  206. 
Horse  nettle,  39. 
Horse-radish,  n. 
Horseweed,  37. 
Husk  tomato,  40. 
Hymenoptera,  149,  169. 
Hyperparasites,  180. 

Ichneumon  flies,  174. 
Insecticides,  155. 
Insectivora,  326. 
Insect-killing  fungi,  271. 
Ironweed,  20. 

Jamestown  lily,  41. 

weed,  41. 
Jimson  weed,  41. 
Joe-pye  weed,  20. 
Johnson-grass,  14,  61. 
Jumping  plant  lice,  82. 
Juniper,  low,  25. 


332 


INDEX 


Kingbird,  301. 

Lacewinged  flies,  171. 
Ladybird,  Australian,  166. 
Lamb-kill,  28. 
Lamb's-quarters,  35,  43. 
Larkspur,  dwarf,  27. 

purple,  27. 

Wyoming,  27. 
Laurel,  mountain,  28. 

sheep,  28. 
Leaf  hoppers,  78,  94. 

apple-tree,  81. 

grape,  80. 

rose,  81. 
Leaf  miners,  115,  129,  130. 

rollers,  115. 
Leaf  roller,  rose,  115. 
Lemon  rot,  224. 
Lepidoptera,  96,  207. 
Lettuce,  prickly,  6. 
Lima  bean  mildew,  223. 
Live- forever,  10. 
Loco  weed,  stemless,  26. 

woolly,  26. 
Locust,  black,  25. 

honey,  25. 

yellow,  25. 
Locustidae,  69. 
Locusts,  long-horned,  69. 

short-horned,  67. 

Mad  apple,  41. 
Mantids,  71,  171. 
Marmots,  310. 
Meadow  lark,  292. 
Mice,  field,  312. 

meadow,  312,  320. 

pine,  315. 

prairie,  314. 

white-footed,  318. 
Microgaster  flies,  177. 
Microtus  pennsylvanicus,  312. 
Mildew,  bean,  254. 

cherry,  254. 

gooseberry,  254. 


Mildew,  grape,  223,  254. 

Lima  bean,  222. 

melon,  223. 

onion,  223. 
Mildews,  downy,  219. 

powdery,  252,  258. 
Milkweed,  23. 
Molds,  215. 

Morning  glory,  wild,  41. 
Moth,  brown-tail,  106,  121. 

Cecropia,  102. 

Luna,  102. 

Polyphemus,  102. 

Promethea,  103. 
Muridae,  312. 
Mushrooms,  215,  224. 
Mustard,  black,  33,  48. 

English,  47. 

hedge,  48. 

tall,  48. 

tumbling,  48. 

wild,  33,  47. 

Noctuidae,  107. 

Oak  twig  pruner,  141. 
Oats,  wild,  4,  7. 

smut,  226,  229. 
Old-witch-grass,  32. 
Onion  maggot,  1 28. 

mildew,  223. 

smut,  229. 
Orange-dog  caterpillars,  98. 

fruit  fly,  124. 

maggot,  126. 
Orthoptera,  65. 
Owlet  moths,  107. 

Papilionina,  97. 
Parasite,  plant-louse,  178. 

primary,  180. 

secondary,  180. 

tertiary,  180. 
Parasitic  fungi,  218. 
Peach,  leaf  curl,  243. 

twig  borer,  116. 


INDEX 


333 


Peach,  worm,  116. 
Pear  blight,  259,  263. 

leaf  blight,  249. 

midge,  124. 

scab,  245. 
Pelecinus  fly,  185. 
Pentatomidae,  166. 
Peppergrass,  33. 
Phcebe,  301. 
Phy corny cetes,  219. 
Phymatidae,  167. 
Physalis,  40. 
Pigeon-grass,  32. 
Pigweed,  common,  36. 

white,  35,  43. 
Pine  sawyer,  141. 
Plantain,  broad-leaved,  8. 

large-bracted,  21. 

narrow-leaved,  8,  22. 

western,  21. 
Plum,  curculio,  141,  146. 

pockets,  244. 

pollination  of,  200. 
Pocket  gophers,  324. 
Poison  hemlock,  27. 

ivy,  27. 

Pollination  of  flowers,  194. 
Poppy,  corn,  50. 

field,  50. 

Potato  blight,  early,  255. 
late,  219. 

scab,  254. 
Prairie  dog,  310. 
Predaceous,  beetles,  164,  172. 

bugs,  167,  172. 

flies,  168,  172. 

bisects,  163. 
Proctotrypid  flies,  185. 
Psyllidae,  82. 
Puccinia  coronata,  238. 

pruni,  239. 

rubigo-vera,  237. 

Sorghi,  238. 
Purslane,  35,  43. 

Quack-grass,  14,  31,  61. 


Rabbit,  cottontail,  321. 

jack,  321. 

northern,  321. 
Radish,  maggot,  127. 

wild,  33. 
Ragweed,  37. 

giant,  37. 

Railroad  worm,  125. 
Rat,  brown,  319. 
Rattlebox,  27. 
Rattleweed,  27. 
Redroot,  36. 
Reduviidae,  168. 
Rib-grass,  22. 
Ribwort,  22. 
Robber  flies,  168. 
Robin,  294,  298. 
Roman  wormwood,  37. 
Root  maggots,  126,  130. 
Rose,  bug,  133. 

chafer,  133,  148. 
Rust,  apple,  238. 

asparagus,  231. 

cedar,  238. 

clover,  234. 

corn,  238. 

hollyhock,  240. 

oats,  238. 

plum,  239. 

raspberry,  239. 

rose,  235. 

wheat  stem,  235. 
leaf,  237. 
Rusts,  231,  240. 

St.  Johnsworts,  23. 
Salsify,  n. 
Sassafras,  25. 
Savin,  25. 
Sawflies,  149. 
Sawfly,  willow,  150. 
Scale,  black,  85. 

cottony  maple,  83. 

insects,  82. 

San  Jose,  86. 
Seventeen-year  locust,  78. 


334 


INDEX 


Sheep  sorrel,  22. 
Shepherd's  purse,  34. 
Smut  fungi,  226. 
Sneeze  weed,  27. 
Soapwort,  10. 
Soldier  bugs,  167. 
Sorrel,  field,  22. 

sheep,  22. 
Sparrow,  chipping,  296. 

English,  297. 
Sparrows,  293,  296. 
Spanish  needles,  19. 
Sphingidae,  100. 
Sphinx  moths,  100,  119,  208. 

Pandorus,  101. 
Squash,  blossoms,  196,  211. 

bug,  73,  94. 
Squirrel-tail  grass,  15. 
Stick-tights,  19. 
Strawberry,  barren,  23. 

blossoms,  198,  211. 

leaf  spot,  250. 

wild,  23. 
Sumach,  dwarf,  29. 

mountain,  29. 

poison,  29. 

smooth,  29. 

staghorn,  29. 

velvet,  29. 
Sundrops,  10. 
Sunflower,  wild,  19. 
Superparasitism,  181. 
Sweet  clover,  n. 

fern,  13,  25. 
Syrphidae,  169. 
Syrphus  flies,  169. 

Tachina  flies,  188. 
Tachina  fly,  large-horned,  190. 
Tachinidae,  188. 
Tansy,  n. 
Teasel,  10. 

Tent  caterpillars,  103,  186. 
Tenthredinidae,  149. 
Thistle,  Canada,  18. 
pasture,  17. 


Thistle,  Russian,  150. 

Thorn  apple,  41. 

Tickle-grass,  15. 

Tineina,  116. 

Tipulidae,  126. 

Toadflax,  n. 

Toadstools,  215. 

Tomato  worms,  101. 

Tomato,  strawberry,  40. 

Tomato  fruit  worm,  in. 

Tortricina,  115. 

Tree  hoppers,  79. 

Trumpet  miner,  apple-leaf,  116. 

Tumbleweed,  36. 

Russian,  50. 
Turnip  maggot,  127. 

Uredinales,  231. 
Ustiliginales,  226. 

Varying  hare,  321. 
Vegetable  oyster,  u. 
Verbena,  wild,  20. 
Vervain,  20. 
Vespidae,  170. 
Voles,  312. 

Walking  sticks,  71,  72. 
Wasps,  social,  170. 

solitary,  170. 
Webworm,  fall,  105,  186. 
Wheat  jointworm,  153. 

midge,  124. 
Wheel  bug,  168. 
White  fly  fungi,  273. 
White  grub,  131. 
White-tops,  19. 
Whiteweed,  16. 
Willow-herb,  9. 

Wire-grass,  14. 
Wire  worms,  134. 
Witch-grass,  14,  31. 
Woodchuck,  310. 

Yarrow,  n. 


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